1
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Wang T, Xu Z, Shi H, Zhao Y, Gao W, Xu Y, Zhang Q. Enhancement of alkaline pretreatment-anaerobically digested sludge dewaterability by chitosan and rice husk powder for land use of biogas slurry. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2024; 369:122356. [PMID: 39217906 DOI: 10.1016/j.jenvman.2024.122356] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/07/2024] [Revised: 07/02/2024] [Accepted: 08/30/2024] [Indexed: 09/04/2024]
Abstract
Alkaline pretreatment can improve the methane yields and dewatering performance of anaerobically digested sludge, but it still needs to be coupled with other conditioning methods in the practical dewatering process. This study utilized four different flocculants and a skeleton builder for conditioning of alkaline pretreatment-anaerobically digested sludge. Chitosan was found to be the most effective in dewatering the sludge. Chitosan coupled with rice husk powder further improved the dewatering performance, which reduced normalized capillary suction time, specific resistance to filtration, and moisture content by 98.7%, 82.0%, and 12.1%. For land use of biogas slurry as a fertilizer, chitosan conditioning promoted the growth of corn seedlings, while the other three flocculants diminished the growth of corn seedlings. Chitosan coupled with rice husk powder further promoted the growth of corn seedlings by 103.5%, 65.0%, and 53.7% in fresh weight, dry weight, and root length, respectively. Overall, chitosan coupled with rice husk powder not only enhanced the dewaterability of alkaline pretreatment-anaerobically digested sludge but also realized the resource utilization of agricultural waste.
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Affiliation(s)
- Tianfeng Wang
- College of Petrochemical Engineering, Lanzhou University of Technology, Lanzhou, 730050, China.
| | - Ziying Xu
- College of Petrochemical Engineering, Lanzhou University of Technology, Lanzhou, 730050, China
| | - Hailong Shi
- College of Petrochemical Engineering, Lanzhou University of Technology, Lanzhou, 730050, China
| | - Yanbin Zhao
- College of Petrochemical Engineering, Lanzhou University of Technology, Lanzhou, 730050, China
| | - Wenqi Gao
- School of Civil Engineering, Lanzhou Institute of Technology, Lanzhou, 730050, China
| | - Yuanshun Xu
- Nanjing Institute of Environmental Sciences, Ministry of Ecology and Environment of the People's Republic of China, Nanjing, 210042, China
| | - Qingfang Zhang
- College of Petrochemical Engineering, Lanzhou University of Technology, Lanzhou, 730050, China
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2
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Yang N, Yang S. Neglected sludge solid phase in sludge pretreatment process: Physicochemical characterization and mechanism study of its role in anaerobic degradation. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 944:173769. [PMID: 38848921 DOI: 10.1016/j.scitotenv.2024.173769] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/21/2024] [Revised: 06/01/2024] [Accepted: 06/02/2024] [Indexed: 06/09/2024]
Abstract
The low anaerobic digestion efficiency of the solid phase separated from pre-treated sludge indicates the need to explore other suitable resource utilization pathways for sludge solid phase. However, there is a lack of comprehensive and in-depth research on the physicochemical properties of sludge solid phase. This study comprehensively analyzes the characteristics of sludge solid phase and elucidates the mechanism of sludge solid phase in the anaerobic degradation of toxic wastewater. The results show that the surface free energy of sludge solid phase after different pre-treatments is mainly contributed by Lewis acid-base hydration free energy. The distribution of proteins on the surface of sludge solid phase plays a major role in the adhesion between sludge solid particles. Metal ions in the sludge solid phase are mainly present in the exchange state, followed by the carbonate state and the organics-bound state. The sludge solid phase obtained by sludge pH 12 + 150 °C treatment has the highest conductivity (1.36 mS/m) and capacitance (25.51 μF/g), mainly due to the presence of melanoidins in the sludge solid phase, which has similar semiquinone radicals to humic acids, thus increasing conductivity. The addition of sludge solid phase promotes an increase in cumulative methane production and rate of methane production. The sludge solid phase might play a role of an auxiliary carbon source acting as an adsorbent to buffer against toxicity inhibition and facilitate electron transfer. This study reveals the characteristics of sludge solid phase and its role in anaerobic digestion, providing theoretical guidance for finding suitable resource utilization pathways for sludge solid phase.
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Affiliation(s)
- Ning Yang
- Department of Environmental Engineering, Xi'an Jiaotong University, Xi'an 710049, China
| | - Shucheng Yang
- Department of Environmental Engineering, Xi'an Jiaotong University, Xi'an 710049, China.
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3
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Yang X, Niu S, Li M, Niu Y, Shen K, Dong B, Hur J, Li X. Leaching behavior of microplastics during sludge mechanical dewatering and its effect on activated sludge. WATER RESEARCH 2024; 266:122395. [PMID: 39255567 DOI: 10.1016/j.watres.2024.122395] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/03/2024] [Revised: 08/16/2024] [Accepted: 09/03/2024] [Indexed: 09/12/2024]
Abstract
Dewatering is an indispensable link in sludge treatment, but its effect on the microplastics (MPs) remains inadequately understood. This study investigated the physicochemical changes and leaching behavior of MPs during the mechanical dewatering of sludge, as well as the impact of MP leachates on activated sludge (AS). After sludge dewatering, MPs exhibit rougher surfaces, decreased sizes and altered functional groups due to the addition of dewatering agents and the application of mechanical force. Meanwhile, plastic additives, depolymerization products, and derivatives of their interactions are leached from MPs during sludge dewatering process. The concentration of MP-based leachates in sludge is 2-25 times higher than that in water. The enhancement of pH and ionic strength caused by dewatering agents induces the release of MP leachates enriched with protein-like, fulvic acid-like, and soluble microbial by-product-like substances. The reflux of MP leachates in sludge dewatering liquor to the wastewater treatment system negatively impacts AS, leading to a decrease in COD removal rate and inhibition of the extracellular polymeric substances secretion. More importantly, MP leachates cause oxidative stress to microbial cells and alter the microbial community structure of AS at the phylum and genus levels. These findings confirm that MPs undergo aging and leaching during sludge dewatering process, and MP leachates may negatively affect the wastewater treatment system.
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Affiliation(s)
- Xingfeng Yang
- School of Environmental and Chemical Engineering, Shanghai University, Shanghai 200444, PR China
| | - Shiyu Niu
- School of Environmental and Chemical Engineering, Shanghai University, Shanghai 200444, PR China
| | - Man Li
- School of Environmental and Chemical Engineering, Shanghai University, Shanghai 200444, PR China
| | - Yulong Niu
- School of Environmental and Chemical Engineering, Shanghai University, Shanghai 200444, PR China
| | - Kailiang Shen
- School of Environmental and Chemical Engineering, Shanghai University, Shanghai 200444, PR China
| | - Bin Dong
- State Key Laboratory of Pollution Control and Resources Reuse, National Engineering Research Center for Urban Pollution Control, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, PR China.
| | - Jin Hur
- Department of Environment and Energy, Sejong University, 209 Neungdong-ro, Gwangjin-gu, Seoul 05006, South Korea
| | - Xiaowei Li
- School of Environmental and Chemical Engineering, Shanghai University, Shanghai 200444, PR China.
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4
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Zhang Z, Liu C, Ouyang B, Fu ML, Xu L, Lan H, Yuan B. A systematic investigation of peracetic acid oxidation and polymeric coagulants re-flocculation to enhance activated sludge dewatering: Multi-porous skeleton structures. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2024; 367:121946. [PMID: 39079495 DOI: 10.1016/j.jenvman.2024.121946] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/15/2024] [Revised: 07/20/2024] [Accepted: 07/23/2024] [Indexed: 08/15/2024]
Abstract
In this research, the effects of peracetic acid (PAA), polymeric flocculants, and their combined conditioning on improving the dewatering performance were comprehensively evaluated. The results showed that sludge cake moisture content, capillary suction time (CST), and specific resistance to filtration (SRF) were 70.6%, 48.1 s, and 3.42 × 1012 m/kg after adding 0.10 g/gMLSS PAA for 50 min, representing reductions of 12.60%, 40.32%, and 33.98%, respectively. Additionally, conditioning of sludge with polyferric sulfate (PFS), polyaluminum chloride (PAC), and cationic polyacrylamide (CPAM) enhanced sludge properties in the following order: CPAM > PAC > PFS. After the PAA oxidation and re-flocculation process, the optimal dosages of PFS, PAC, and CPAM were reduced to 1.5 g/L, 0.9 g/L, and 0.04 g/L, respectively. The sludge dewatering performance significantly improved, with sludge cake moisture content measuring 65.8%, 66.3%, and 61.7%, respectively. Moreover, the spatial multi-porous skeleton structures were formed via re-flocculation to improve the sludge dewatering. Furthermore, economic evaluation validated that the pre-oxidation and re-flocculation process could be considered an economically viable option. These research findings could serve as a valuable reference for practical engineering applications.
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Affiliation(s)
- Zhiyong Zhang
- Xiamen Key Laboratory of Municipal and Industrial Solid Waste Utilization and Pollution Control, College of Civil Engineering, Huaqiao University, Xiamen, Fujian 361021, China; Center for Water and Ecology, State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing 100084, China
| | - Chunxiao Liu
- Xiamen Key Laboratory of Municipal and Industrial Solid Waste Utilization and Pollution Control, College of Civil Engineering, Huaqiao University, Xiamen, Fujian 361021, China
| | - Boda Ouyang
- Xiamen Key Laboratory of Municipal and Industrial Solid Waste Utilization and Pollution Control, College of Civil Engineering, Huaqiao University, Xiamen, Fujian 361021, China
| | - Ming-Lai Fu
- Xiamen Key Laboratory of Municipal and Industrial Solid Waste Utilization and Pollution Control, College of Civil Engineering, Huaqiao University, Xiamen, Fujian 361021, China.
| | - Lei Xu
- Xiamen Key Laboratory of Municipal and Industrial Solid Waste Utilization and Pollution Control, College of Civil Engineering, Huaqiao University, Xiamen, Fujian 361021, China
| | - Huachun Lan
- Center for Water and Ecology, State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing 100084, China
| | - Baoling Yuan
- Xiamen Key Laboratory of Municipal and Industrial Solid Waste Utilization and Pollution Control, College of Civil Engineering, Huaqiao University, Xiamen, Fujian 361021, China; Key Laboratory of Songliao Aquatic Environment, Ministry of Education, School of Municipal and Environmental Engineering, Jilin Jianzhu University, Changchun, 130118, China.
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5
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Ramanathan T, Ollivier Q, Rahman A, Hamilton L, Arumugam S. Long-term dissolved organic carbon changes in Woronora drinking water system in Australia. CHEMOSPHERE 2024; 364:143047. [PMID: 39121958 DOI: 10.1016/j.chemosphere.2024.143047] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/23/2024] [Revised: 07/24/2024] [Accepted: 08/06/2024] [Indexed: 08/12/2024]
Abstract
Assessing historical records of DOC concentrations (DOC) in drinking water sources is important for water utilities to understand long-term planning for infrastructure needs. This study investigates 15-20 years of historical data of the Woronora water supply catchment in Australia inclusive of the water filtration plant (WFP), the lake from where the water was drawn for WFP supply, and the two primary river inputs. The DOC at each site ranged from 0.8 mg L-1 to 13.9 mg L-1, with the highest and lowest concentrations observed in Waratah Rivulet. The DOC in the lake and WFP significantly (p < 0.001) increased at annual change rates of 0.192 and 0.180 mg L-1 yr-1. However, Woronora River showed a ∼50% lower rate of DOC increase at 0.096 mg L-1 yr-1 (p < 0.001), while Waratah Rivulet showed no trend (p > 0.05). UV254 also showed increasing trends at Woronora River, Lake Woronora, and Woronora WFP, indicating an increase in aromatic DOC compounds in all three sites. Waratah Rivulet, however, transported more than 60% of the total DOC load into Lake Woronora due to high flow volumes (more than 65% of total annual system flow). Annual DOC load to the lake is positively correlated with annual rainfall (R2 > 0.92; p < 0.001). The higher percentage (>73%) of the samples had SUVA254 greater than 2 L mg -1 m-1 in all four sites indicating a dominance of hydrophobic DOC. The terrestrial plant-derived DOC has increased in Lake Woronora, predominantly influenced by historical rainfall magnitude. The results underscore the importance of considering the impact of increased DOC at the treatment plant intake for the planning and operation of the Woronora water supply system.
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Affiliation(s)
- Thusyanthini Ramanathan
- School of Engineering, Design and Built Environment Western Sydney University, NSW, 2747, Australia.
| | | | - Ataur Rahman
- School of Engineering, Design and Built Environment Western Sydney University, NSW, 2747, Australia.
| | | | - Sathasivan Arumugam
- School of Engineering, Design and Built Environment Western Sydney University, NSW, 2747, Australia.
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6
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Xiao Z, Fang Q, Zhou W, Ding W, Zhu J, Guo X, Liang G. Enhanced hydrolysis of waste activated sludge and recovery of volatile fatty acids: Performance and mechanistic analysis of synergistic treatment with sodium citrate and calcium oxide. BIORESOURCE TECHNOLOGY 2024; 407:131143. [PMID: 39043280 DOI: 10.1016/j.biortech.2024.131143] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/27/2024] [Revised: 06/30/2024] [Accepted: 07/19/2024] [Indexed: 07/25/2024]
Abstract
Anaerobic fermentation has emerged as a promising method of transforming waste activated sludge into high-value products (e.g., volatile fatty acids (VFAs)). This work developed sodium citrate (SC)-calcium oxide (CaO) pretreatment to accelerate the production of VFAs by enhancing sludge solubilization and disintegration of extracellular polymeric substances. The results showed that co-pretreatment with 0.25 g/g TSS of SC and 0.05 g/g TSS of CaO effectively boosted VFAs accumulation (5823.3 mg COD/L), which was 12.2 times higher than the Control group. SC-CaO pretreatment enhanced hydrolysis and acidogenesis by providing ample organic substrates, thereby promoting the growth of hydrolytic and acidogenic bacteria. Additionally, the fermentation broth resulting from co-pretreatment exhibited lower phosphorus concentration and higher biodegradability. Economic analysis confirmed that the combined pretreatment is cost-effective. This work provides a viable strategy for enhancing high-value product recovery from sludge.
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Affiliation(s)
- Zilong Xiao
- Department of Municipal Engineering, College of Civil and Transportation Engineering, Guangzhou University, Guangzhou, PR China
| | - Qian Fang
- Department of Municipal Engineering, College of Civil and Transportation Engineering, Guangzhou University, Guangzhou, PR China.
| | - Wuyang Zhou
- Department of Municipal Engineering, College of Civil and Transportation Engineering, Guangzhou University, Guangzhou, PR China; Research Center, Guangzhou Municipal Engineering Design & Research Institute CO., Ltd, Guangzhou, PR China
| | - Wenxue Ding
- Guangzhou Sciencecity Drainage Management CO., Ltd, Guangzhou, PR China
| | - Jiang Zhu
- Department of Municipal Engineering, College of Civil and Transportation Engineering, Guangzhou University, Guangzhou, PR China
| | - Xiaomin Guo
- Department of Municipal Engineering, College of Civil and Transportation Engineering, Guangzhou University, Guangzhou, PR China
| | - Guirong Liang
- Department of Municipal Engineering, College of Civil and Transportation Engineering, Guangzhou University, Guangzhou, PR China
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7
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Cheng S, Chen L, Wang S, Yao K, Tian H. Insights into the Synergistic Effect and Inhibition Mechanism of Composite Conditioner on Sulfur-Containing Gases during Sewage Sludge Pyrolysis. Molecules 2024; 29:4110. [PMID: 39274958 PMCID: PMC11396920 DOI: 10.3390/molecules29174110] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2024] [Revised: 08/26/2024] [Accepted: 08/26/2024] [Indexed: 09/16/2024] Open
Abstract
Sewage sludge odorous gas release is a key barrier to resource utilization, and conditioners can mitigate the release of sulfur-containing gases. The gas release characteristics and sulfur compound distribution in pyrolysis products under both single and composite conditioning strategies of CaO, Fe2O3, and FeCl3 were investigated. This study focused on the inhibition mechanisms of these conditioners on sulfur-containing gas emissions and compared the theoretical and experimental sulfur content in the products to evaluate the potential synergistic effects of the composite conditioners. The findings indicated that at 650 °C, CaO, Fe2O3, and FeCl3 inhibited H2S release by 35.8%, 23.2%, and 9.1%, respectively. Notably, the composite of CaO with FeCl3 at temperatures ranging from 350 to 450 °C and the combination of Fe2O3 with FeCl3 at 650 °C were found to exert synergistic suppression on H2S emissions. The strongly alkaline CaO inhibited the metathesis reaction between HCl, a decomposition product of FeCl3, and the sulfur-containing compounds within the sewage sludge, thereby exerting a synergistic suppression on the emission of H2S. Conversely, at temperatures exceeding 550 °C, the formation of Ca-Fe compounds, such as FeCa2O4, appeared to diminish the sulfur-fixing capacity of the conditioners, resulting in increased H2S emissions. For instance, the combination of CaO and FeCl3 at 450 °C was found to synergistically reduce H2S emissions by 56.3%, while the combination of CaO and Fe2O3 at 650 °C synergistically enhances the release of H2S by 23.6%. The insights gained from this study are instrumental in optimizing the pyrolysis of sewage sludge, aiming to minimize its environmental footprint and enhance the efficiency of resource recovery.
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Affiliation(s)
- Shan Cheng
- School of Energy and Power Engineering, Changsha University of Science and Technology, Changsha 410114, China
| | - Lianghui Chen
- School of Energy and Power Engineering, Changsha University of Science and Technology, Changsha 410114, China
| | - Shaoshuo Wang
- School of Energy and Power Engineering, Changsha University of Science and Technology, Changsha 410114, China
| | - Kehui Yao
- School of Energy and Power Engineering, Changsha University of Science and Technology, Changsha 410114, China
| | - Hong Tian
- School of Energy and Power Engineering, Changsha University of Science and Technology, Changsha 410114, China
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8
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Xu HY, Yang X, Yu R, Zuo T, Liu Q, Jia S, Jia LY. Adsorption properties of cellulose-derived hydrogel and magnetic hydrogels from Sophora flavescens on Cu 2+ and Congo red. Int J Biol Macromol 2024; 274:133209. [PMID: 38906348 DOI: 10.1016/j.ijbiomac.2024.133209] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2023] [Revised: 05/11/2024] [Accepted: 06/14/2024] [Indexed: 06/23/2024]
Abstract
This study synthesized a robust, magnetically responsive hydrogel from Sophora flavescens-modified cellulose and chitosan, employing Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), thermogravimetric analysis (TGA and DTG), and scanning electron microscopy (SEM) to confirm the preservation of cellulose's intrinsic properties and the hydrogel's remarkable elasticity, toughness, and porosity. These hydrogels integrate cellulose's structural backbone with functional moieties from chitosan, enhancing adsorption capabilities for Cu2+ ions and Congo red (CR) dye. Kinetic and thermodynamic analyses reveal that adsorption is spontaneous and endothermic, following a pseudo-second-order model and the Freundlich isotherm. Notably, Cu2+ adsorption capacity increases with pH, while CR adsorption initially decreases before rising, demonstrating the hydrogels' potential as effective, sustainable adsorbents for removing pollutants from water.
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Affiliation(s)
| | - XianWen Yang
- Third Institute of Oceanography, Ministry of Natural Resources, China
| | - RunPing Yu
- Shenyang Pharmaceutical University, China
| | - Ting Zuo
- Shenyang Pharmaceutical University, China
| | - QiuYue Liu
- Shenyang Pharmaceutical University, China
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9
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Zeng Y, Wang Z, Tan Q, Shen Y, Sun J, Shen L, Teng J, Lin H. Enhanced sludge dewatering using a novel synergistic iron/peroxymonosulfate-polyacrylamide method. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2024; 365:121638. [PMID: 38959766 DOI: 10.1016/j.jenvman.2024.121638] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/21/2024] [Revised: 06/17/2024] [Accepted: 06/27/2024] [Indexed: 07/05/2024]
Abstract
In the sludge dewatering process, a formidable challenge arises due to the robust interactions between extracellular polymeric substances (EPS) and bound water. This study introduces a novel, synergistic conditioning method that combines iron (Fe2+)/peroxymonosulfate (PMS) and polyacrylamide (PAM) to significantly enhance sludge dewatering efficiency. The application of the Fe2+/PMS-PAM conditioning method led to a substantial reduction in specific filtration resistance (SFR) by 82.75% and capillary suction time (CST) by 80.44%, marking a considerable improvement in dewatering performance. Comprehensive analyses revealed that pre-oxidation with Fe2+/PMS in the Fe2+/PMS-PAM process effectively degraded EPS, facilitating the release of bound water. Subsequently, PAM enhanced the flocculation of fine sludge particles resulting from the advanced oxidation processes (AOPs). Furthermore, analysis based on the Extended Derjaguin-Landau-Verwey-Overbeek (XDLVO) theory demonstrated shifts in interaction energies, highlighting the breakdown of energy barriers within the sludge and a transition in surface characteristics from hydrophilic (3.79 mJ m-2) to hydrophobic (-61.86 mJ m-2). This shift promoted the spontaneous aggregation of sludge particles. The innovative use of the Flory-Huggins theory provided insights into the sludge filtration mechanism from a chemical potential perspective, linking these changes to SFR. The introduction of Fe2+/PMS-PAM conditioning disrupted the uniformity of the EPS-formed gel layer, significantly reducing the chemical potential difference between the permeate and the water in the gel layer, leading to a lower SFR and enhanced dewatering performance. This thermodynamic approach significantly enhances our understanding of sludge dewatering and conditioning. These findings represent a paradigm shift, offering innovative strategies for sludge treatment and expanding our comprehension of dewatering and conditioning techniques.
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Affiliation(s)
- Yansha Zeng
- College of Geography and Environmental Sciences, Zhejiang Normal University, Jinhua, 321004, China; Key Laboratory of Watershed Earth Surface Processes and Ecological Security, Zhejiang Normal University, Jinhua, 321004, China.
| | - Zhe Wang
- College of Geography and Environmental Sciences, Zhejiang Normal University, Jinhua, 321004, China; Key Laboratory of Watershed Earth Surface Processes and Ecological Security, Zhejiang Normal University, Jinhua, 321004, China.
| | - Qiyin Tan
- College of Geography and Environmental Sciences, Zhejiang Normal University, Jinhua, 321004, China; Key Laboratory of Watershed Earth Surface Processes and Ecological Security, Zhejiang Normal University, Jinhua, 321004, China.
| | - Yue Shen
- College of Geography and Environmental Sciences, Zhejiang Normal University, Jinhua, 321004, China; Key Laboratory of Watershed Earth Surface Processes and Ecological Security, Zhejiang Normal University, Jinhua, 321004, China.
| | - Jiahao Sun
- College of Geography and Environmental Sciences, Zhejiang Normal University, Jinhua, 321004, China; Key Laboratory of Watershed Earth Surface Processes and Ecological Security, Zhejiang Normal University, Jinhua, 321004, China.
| | - Liguo Shen
- College of Geography and Environmental Sciences, Zhejiang Normal University, Jinhua, 321004, China; Key Laboratory of Watershed Earth Surface Processes and Ecological Security, Zhejiang Normal University, Jinhua, 321004, China.
| | - Jiaheng Teng
- College of Geography and Environmental Sciences, Zhejiang Normal University, Jinhua, 321004, China; Key Laboratory of Watershed Earth Surface Processes and Ecological Security, Zhejiang Normal University, Jinhua, 321004, China.
| | - Hongjun Lin
- College of Geography and Environmental Sciences, Zhejiang Normal University, Jinhua, 321004, China; Key Laboratory of Watershed Earth Surface Processes and Ecological Security, Zhejiang Normal University, Jinhua, 321004, China.
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10
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Liu Y, Niu X, Zhang D, Zhou L, Tao C, Lin Y, Chen S, Chen Y, Lin Z, Kong S. Insight into enhancing the performance of sludge dewatering using a novel flocculant CS-TA prepared through free radical-mediated conjugation. ENVIRONMENTAL TECHNOLOGY 2024:1-18. [PMID: 39010782 DOI: 10.1080/09593330.2024.2377797] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/03/2024] [Accepted: 05/15/2024] [Indexed: 07/17/2024]
Abstract
Flocculation is one of the most significant conditioning methods for sludge dewatering. In the study, a novel flocculant CS-TA, prepared through free radical-mediated conjugation of tannic acid (TA) and chitosan (CS), was proposed to improve sludge dewatering. The characterisation using Fourier transform infra-red spectroscopy and X-ray diffraction analysis shows that the CS chain was the backbone of CS-TA, and the presence of CS-TA aromatic rings confirmed the conjugation of CS with TA. Moreover, the conditioning of CS-TA yielded the best dewatering performance at 30 mg g TS-1 with the water content of sludge cake by press filtration (Wsc) of 59.78% ± 0.3% and capillary suction time (CST) of 11.8s ± 0.35 s, compared to 98.2% ± 0.15% and 56.2 s ± 0.16 in raw sludge. The results of different influencing factors (e.g. pH and temperature) on flocculation efficiency indicated that CS-TA possessed the capacity for enhancing sludge dewaterability over a wide range of pH, and the optimal temperature was observed to be 35 °C. Furthermore, the increase of particle size and zeta potential implied the addition of CS-TA favoured the formation of larger particles charge neutralisation and adsorption bridging effect. In addition, extracellular polymer substances (EPS) analysis indicated that the decrease in the polysaccharide and protein contents in EPS after CS-TA addition could increase the relative hydrophobicity of sludge. Moreover, the contents of heavy metals in sludge and their leaching toxicity and environmental risk were reduced. This study provides comprehensive insights into the exploration of CS-TA for sludge dewatering and the maintenance of ecological security in an eco-friendly.
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Affiliation(s)
- Yuejin Liu
- School of Environment and Energy, South China University of Technology, Guangzhou, People's Republic of China
| | - Xiaojun Niu
- School of Environment and Energy, South China University of Technology, Guangzhou, People's Republic of China
- School of Environmental Science and Engineering, Guangdong University of Petrochemical Technology, Maoming, People's Republic of China
- The Key Lab of Pollution Control and Ecosystem Restoration in Industry Clusters, Ministry of Education, South China University of Technology, Guangzhou Higher Education Mega Centre, Guangzhou, People's Republic of China
| | - Dongqing Zhang
- School of Environmental Science and Engineering, Guangdong University of Petrochemical Technology, Maoming, People's Republic of China
| | - Lingling Zhou
- School of Environment and Energy, South China University of Technology, Guangzhou, People's Republic of China
| | - Chunyang Tao
- School of Environment and Energy, South China University of Technology, Guangzhou, People's Republic of China
| | - Yu Lin
- Guangzhou Urban Drainage Company Limited, Guangzhou, People's Republic of China
| | - Siping Chen
- School of Environmental Science and Engineering, Guangdong University of Petrochemical Technology, Maoming, People's Republic of China
| | - Yawen Chen
- School of Environmental Science and Engineering, Guangdong University of Petrochemical Technology, Maoming, People's Republic of China
| | - Zhang Lin
- School of Environment and Energy, South China University of Technology, Guangzhou, People's Republic of China
| | - Suying Kong
- School of Environmental Science and Engineering, Guangdong University of Petrochemical Technology, Maoming, People's Republic of China
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11
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Zhang S, Yi X, He D, Tang X, Chen Y, Zheng H. Recent progress and perspectives of typical renewable bio-based flocculants: characteristics and application in wastewater treatment. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2024; 31:46877-46897. [PMID: 38980480 DOI: 10.1007/s11356-024-34199-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/24/2023] [Accepted: 06/27/2024] [Indexed: 07/10/2024]
Abstract
The research on bio-based flocculants for waste resource utilization and environmental protection has garnered significant attention. Bio-based flocculants encompass plant-based, animal-based, and microbial variants that are prepared and modified through biological, chemical, and physical methods. These flocculants possess abundant functional groups, unique structures, and distinctive characteristics. This review comprehensively discussed the removal rates of conventional pollutants and emerging pollutants by bio-based flocculants, the interaction between these flocculants and pollutants, their impact on flocculation performance in wastewater treatment, as well as their application cost. Furthermore, it described the common challenges faced by bio-based flocculants in practical applications along with various improvement strategies to address them. With their safety profile, environmental friendliness, efficiency, renewability, and wide availability from diverse sources, bio-based flocculants hold great potential for widespread use in wastewater treatment.
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Affiliation(s)
- Shixin Zhang
- School of River and Ocean Engineering, Chongqing Jiaotong University, Chongqing, 400074, People's Republic of China
- Key Laboratory of Hydraulic and Waterway Engineering of the Ministry of Education, Chongqing Jiaotong University, Chongqing, 400074, People's Republic of China
| | - Xiaohui Yi
- School of River and Ocean Engineering, Chongqing Jiaotong University, Chongqing, 400074, People's Republic of China
| | - Dilin He
- School of River and Ocean Engineering, Chongqing Jiaotong University, Chongqing, 400074, People's Republic of China
| | - Xiaomin Tang
- Chongqing Key Laboratory of Catalysis & Functional Organic Molecules, College of Environment and Resources, Chongqing Technology and Business University, Chongqing, 400067, People's Republic of China
| | - Yao Chen
- School of River and Ocean Engineering, Chongqing Jiaotong University, Chongqing, 400074, People's Republic of China.
- Key Laboratory of Hydraulic and Waterway Engineering of the Ministry of Education, Chongqing Jiaotong University, Chongqing, 400074, People's Republic of China.
| | - Huaili Zheng
- Key Laboratory of the Three Gorges Reservoir Region's Eco-Environment, State Ministry of Education, Chongqing University, Chongqing, 400045, People's Republic of China
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12
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Zheng Q, Ni L. Analysis of the effect of intrinsic sludge properties on sludge drying characteristics from both sludge composition and type scales. WASTE MANAGEMENT (NEW YORK, N.Y.) 2024; 183:278-289. [PMID: 38781819 DOI: 10.1016/j.wasman.2024.05.020] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/01/2023] [Revised: 04/08/2024] [Accepted: 05/15/2024] [Indexed: 05/25/2024]
Abstract
Convective drying is an effective method for reducing the moisture content of the sludge. Fewer studies have discussed the effect of sludge physicochemical properties on drying compared to air parameters. Eleven types of sludge were collected, and ultimate analysis, proximate analysis, and heat value analysis were performed. Meanwhile, the maximum drying rate (umax) of sludge convection drying at 70 °C was determined. The results showed that the cumulative variance contribution of the two extracted principal components (PCs) was 92.5 %. Then, a regression model of umax was developed based on the extracted PCs. The coefficient of determination of this model was 0.788, and the difference was statistically significant, with a negative correlation between umax and PC2. Further, the principal component score plot enabled the traceability of the integrated sludge, and based on this classification results, the drying characteristics of various types of sludge were discussed, and a high correlation (R2 = 0.9590) between the initial moisture content of sludge and umax was found. Mathematical models between sludge physicochemical properties and drying characteristics can be effectively developed from both sludge composition and type scales. This exploration deepened the knowledge of sludge drying and facilitates the prediction of drying rate.
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Affiliation(s)
- Qiushuang Zheng
- School of Architecture and Design, Harbin Institute of Technology, Key Laboratory of Cold Region Urban and Rural Human Settlement Environment Science and Technology, Ministry of Industry and Information Technology, Harbin, China
| | - Long Ni
- School of Architecture and Design, Harbin Institute of Technology, Key Laboratory of Cold Region Urban and Rural Human Settlement Environment Science and Technology, Ministry of Industry and Information Technology, Harbin, China.
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13
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Zhang H, Liu WH, Gao YY, Sun P, Zeng YP, Ma LL, Wu JN, Zhou SG, Cui XQ, Zeng RJ, Wang HF. A novel approach for sludge deep-dewatering via flowing-out enhancement but not relying on cell lysis and bound water release. WATER RESEARCH 2024; 257:121743. [PMID: 38728775 DOI: 10.1016/j.watres.2024.121743] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/24/2024] [Revised: 04/14/2024] [Accepted: 05/05/2024] [Indexed: 05/12/2024]
Abstract
Effective deep-dewatering is crucial for wastewater sludge management. Currently, the dominant methods focus on promoting cell lysis to release intracellular water, but these techniques often lead to secondary pollution and require stringent conditions, limiting their practical use. This study explores an innovative method using a commercially available complex quaternary ammonium salt surfactant, known as G-agent. This agent remarkably reduces the sludge water content from 98.6 % to 56.8 % with a low dosage (50 mg/g DS) and under neutral pH conditions. This approach surpasses Fenton oxidation in terms of dewatering efficiency and avoids the necessity for cell lysis and bound water release, thereby reducing the risk of secondary pollution in the filtrate, including heavy metals, nitrogen, phosphorus, and other contaminants. The G-agent plays a significant role in destabilizing flocs and enhancing flocculation during the conditioning and initial dewatering stages, effectively reducing the solid-liquid interfacial affinity of the sludge. In the compression filtration stage, the agent's solidification effect is crucial in forming a robust skeleton that improves pore connectivity within the filter cake, leading to increased water permeability, drainage performance and water flow-out efficiency. This facilitates deep dewatering of sludge without cell lysis. The study reveals that the G-agent primarily improves water flow-out efficiency rather than water flowability, indicating that cell lysis and bound water release are not indispensable prerequisites for sludge deep-dewatering. Furthermore, it presents an encouraging prospect for overcoming the limitations associated with conventional sludge deep-dewatering processes.
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Affiliation(s)
- Hao Zhang
- Fujian Provincial Key Laboratory of Soil Environmental Health and Regulation, College of Resources and Environment, Fujian Agriculture and Forestry University, Fuzhou 350002, China
| | - Wen-Hui Liu
- Fujian Provincial Key Laboratory of Soil Environmental Health and Regulation, College of Resources and Environment, Fujian Agriculture and Forestry University, Fuzhou 350002, China
| | - Yun-Yan Gao
- Fujian Provincial Key Laboratory of Soil Environmental Health and Regulation, College of Resources and Environment, Fujian Agriculture and Forestry University, Fuzhou 350002, China
| | - Ping Sun
- Fujian Provincial Key Laboratory of Soil Environmental Health and Regulation, College of Resources and Environment, Fujian Agriculture and Forestry University, Fuzhou 350002, China
| | - Yuan-Ping Zeng
- Fujian Provincial Key Laboratory of Soil Environmental Health and Regulation, College of Resources and Environment, Fujian Agriculture and Forestry University, Fuzhou 350002, China
| | - Lin-Lin Ma
- Instrumental Analysis Center, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Jiang-Nan Wu
- Fujian Haixia Environmental Protection Group Co.,Ltd, Fuzhou 350002, China
| | - Shun-Gui Zhou
- Fujian Provincial Key Laboratory of Soil Environmental Health and Regulation, College of Resources and Environment, Fujian Agriculture and Forestry University, Fuzhou 350002, China
| | - Xi-Qin Cui
- Fujian Provincial Key Laboratory of Soil Environmental Health and Regulation, College of Resources and Environment, Fujian Agriculture and Forestry University, Fuzhou 350002, China.
| | - Raymond Jianxiong Zeng
- Fujian Provincial Key Laboratory of Soil Environmental Health and Regulation, College of Resources and Environment, Fujian Agriculture and Forestry University, Fuzhou 350002, China.
| | - Hou-Feng Wang
- Fujian Provincial Key Laboratory of Soil Environmental Health and Regulation, College of Resources and Environment, Fujian Agriculture and Forestry University, Fuzhou 350002, China.
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Jiang T, Li X, Yang J, Wang L, Wang W, Zhang L, Wang B. Potential of free nitrous acid (FNA) for sludge treatment and resource recovery from waste activated sludge: A review. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2024; 360:121170. [PMID: 38749134 DOI: 10.1016/j.jenvman.2024.121170] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/27/2023] [Revised: 04/18/2024] [Accepted: 05/11/2024] [Indexed: 06/05/2024]
Abstract
The escalating production of waste activated sludge (WAS) presents significant challenges to wastewater treatment plants (WWTPs). Free nitrous acid (FNA), known for its biocidal effect, has gained a growing focus on sludge dewatering, sludge reduction, and resource recovery from WAS due to its eco-friendly and cost-effective properties. Nevertheless, there have been no attempts made to systematically summarize or critically analyze the application of FNA in enhancing treatment and resource utilization of sludge. In this paper, we provided an overview of the current understanding regarding the application potential and influencing factors of FNA in sludge treatment, with a specific focus on enhancing sludge dewatering efficiency and reducing volume. To foster resource development from sludge, various techniques based on FNA have recently been proposed, which were comprehensively reviewed with the corresponding mechanisms meticulously discussed. The results showed that the chemical oxidation and interaction with microorganisms of FNA played the core role in improving resource utilization. Furthermore, current challenges and future prospects of the FNA-based applications were outlined. It is expected that this review can refine the theoretical framework of FNA-based processes, providing a theoretical foundation and technical guidance for the large-scale demonstration of FNA.
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Affiliation(s)
- Tan Jiang
- National Engineering Laboratory for Advanced Municipal Wastewater Treatment and Reuse Technology, Engineering Research Center of Beijing, Beijing University of Technology, Beijing 100124, PR China
| | - Xiaodi Li
- National Engineering Laboratory for Advanced Municipal Wastewater Treatment and Reuse Technology, Engineering Research Center of Beijing, Beijing University of Technology, Beijing 100124, PR China
| | - Jiayi Yang
- National Engineering Laboratory for Advanced Municipal Wastewater Treatment and Reuse Technology, Engineering Research Center of Beijing, Beijing University of Technology, Beijing 100124, PR China
| | - Lu Wang
- National Engineering Laboratory for Advanced Municipal Wastewater Treatment and Reuse Technology, Engineering Research Center of Beijing, Beijing University of Technology, Beijing 100124, PR China
| | - Wen Wang
- National Engineering Laboratory for Advanced Municipal Wastewater Treatment and Reuse Technology, Engineering Research Center of Beijing, Beijing University of Technology, Beijing 100124, PR China
| | - Li Zhang
- National Engineering Laboratory for Advanced Municipal Wastewater Treatment and Reuse Technology, Engineering Research Center of Beijing, Beijing University of Technology, Beijing 100124, PR China
| | - Bo Wang
- National Engineering Laboratory for Advanced Municipal Wastewater Treatment and Reuse Technology, Engineering Research Center of Beijing, Beijing University of Technology, Beijing 100124, PR China.
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15
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Lu Y, Huang M, Wang B, Zhou Q, Hu Y, Xue H. Effects of residual foaming agent and defoamer on defoaming-flocculation-filterpress characteristics of earth pressure balance shield muck. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2024; 31:43080-43095. [PMID: 38888824 DOI: 10.1007/s11356-024-33946-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/28/2023] [Accepted: 06/04/2024] [Indexed: 06/20/2024]
Abstract
Foaming agents as a combination of several components are usually used as soil conditioning during earth pressure balance shield (EPBS) tunnelling. These residues in waste EPBS muck lead to a series of new challenges for in-situ recycling, i.e., foams overflow flocculation tank. This study investigates the effects of residual foaming agent components and defoamers on defoaming-flocculation-filterpress characteristics of EPBS muck using an improved flocculation and filterpress system. Residual foam height (Hf), defoaming ratio (DFR), antifoaming ratio (AFR), total suspended substance (TSS), turbidity, moisture content (MC), and zeta potential (ZP) were selected as characterization indices. The microstructure of filterpress cakes was analyzed using a scanning electron microscope. Results demonstrate that an enhancement within 0.0-1.0wt.% for sodium fatty alcohol polyoxyethylene ether sulfate (AES) and alpha olefin sulfonate (AOS) significantly reduces DFR and AFR. The MC and ZP decline, while the Hf and turbidity enhance. The combinations of nonionic surfactants alkyl polyglycoside (APG) and fatty alcohol-polyoxyethylene ether (AEO) in a concentration range of 0.0-1.0wt.% with 0.2wt.% AES causes the Hf, DFR, AFR, turbidity, and ZP to exhibit absolutely different variations. The MC with the growth in both APG and AEO presents a trend of first decreasing and then increasing. By increasing foam stabilizers sodium carboxymethyl cellulose (CMC) and guar gum (GG) within 0.02-0.10wt.%, the AFR, TSS, and ZP enhance in varying degrees, while the Hf, DFR, and MC gradually reduce. With the increase of defoamers hydroxyl silicone oil-glycerol polyoxypropylene ether (H-G) and dimethyl silicone oil-glycerol polyoxypropylene ether (D-G) within 0.002-0.010wt.%, the DFR and AFR are significantly improved, while the TSS, turbidity, MC, and ZP display varying degrees of reduction. Moreover, defoaming-flocculation-filterpress mechanisms of EPBS muck are explored to provide a useful reference for actual in-situ recycling projects.
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Affiliation(s)
- Yao Lu
- School of Civil Engineering, Fuzhou University, Fuzhou, China
| | - Ming Huang
- School of Civil Engineering, Fuzhou University, Fuzhou, China.
| | - Bingnan Wang
- School of Civil Engineering, Fuzhou University, Fuzhou, China
| | - Qi Zhou
- School of Civil Engineering, Fuzhou University, Fuzhou, China
| | - Yanfeng Hu
- Xiamen Branch, CCCC First Highway Engineering Group Co, Ltd., Xiamen, China
| | - Huakun Xue
- Xiamen Branch, CCCC First Highway Engineering Group Co, Ltd., Xiamen, China
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16
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Tang S, Huang S, Chen P, Wu Z, Zhao T. Comprehensive assessment of enhancing dewaterability of dredged sediments by starch-based flocculant. RSC Adv 2024; 14:17547-17556. [PMID: 38828273 PMCID: PMC11140457 DOI: 10.1039/d4ra02189d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2024] [Accepted: 05/25/2024] [Indexed: 06/05/2024] Open
Abstract
Dredged sediment poses significant challenges for transportation and subsequent treatment due to its high water content and large volume. Coagulation, a common method of dewatering, can significantly enhance the dewatering performance of dredged sediment. This study synthesized a cationic starch-based flocculant [starch-3-chloro-2-hydroxypropyl trimethylammonium chloride (St-CTA)] through etherification for the flocculation dewatering of dredged sediment. The effectiveness and mechanism of St-CTA as a dewatering flocculant for dredged sediment were investigated. The results demonstrated that when the dosage of St-CTA was 12 mg g-1 TSS (total suspended solids), the dehydration property of dredged sediment substantially improved, with the specific resistance to filtration (SRF) decreasing by 93.3%, the capillary suction time (CST) by 93.5%, and the water content of the filter cake (WC) by 9.7%. The removal rate of turbidity of the supernatant from the conditioned dredged sediment reached 99.6%, accelerating the settling speed and effectively capturing and separating fine particles from the sediment. St-CTA significantly increased the median particle size (D50), altered the microstructure and extracellular polymeric substances (EPS) of the flocs, and increased the fractal dimension of the flocs, making them more compact and conducive to the formation of drainage channels. These findings confirm the feasibility of using potentially environmentally friendly St-CTA as a rapid dewatering conditioning agent for sediment.
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Affiliation(s)
- Shilei Tang
- School of Environment and Energy, South China University of Technology Higher Education Mega Center Guangzhou 510006 P. R. China
| | - Shaobin Huang
- School of Environment and Energy, South China University of Technology Higher Education Mega Center Guangzhou 510006 P. R. China
| | - Pengfei Chen
- School of Environment and Energy, South China University of Technology Higher Education Mega Center Guangzhou 510006 P. R. China
| | - Zhipeng Wu
- School of Environment and Energy, South China University of Technology Higher Education Mega Center Guangzhou 510006 P. R. China
| | - Tianyu Zhao
- School of Environment and Energy, South China University of Technology Higher Education Mega Center Guangzhou 510006 P. R. China
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17
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Lin W, Chen R, Gong C, Desmond P, He X, Nan J, Li G, Ma J, Ding A, Ngo HH. Sustained oxidation of Tea-Fe(III)/H 2O 2 simultaneously achieves sludge reduction and carbamazepine removal: The crucial role of EPS regulation. JOURNAL OF HAZARDOUS MATERIALS 2024; 470:134182. [PMID: 38583202 DOI: 10.1016/j.jhazmat.2024.134182] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/09/2024] [Revised: 03/28/2024] [Accepted: 03/30/2024] [Indexed: 04/09/2024]
Abstract
Establishing an economic and sustained Fenton oxidation system to enhance sludge dewaterability and carbamazepine (CBZ) removal rate is a crucial path to simultaneously achieve sludge reduction and harmless. Leveraging the principles akin to "tea making", we harnessed tea waste to continually release tea polyphenols (TP), thus effectively maintaining high level of oxidation efficiency through the sustained Fenton reaction. The results illustrated that the incorporation of tea waste yielded more favorable outcomes in terms of water content reduction and CBZ removal compared to direct TP addition within the Fe(III)/hydrogen peroxide (H2O2) system. Concomitantly, this process mainly generated hydroxyl radical (•OH) via three oxidation pathways, effectively altering the properties of extracellular polymeric substances (EPS) and promoting the degradation of CBZ from the sludge mixture. The interval addition of Fe(III) and H2O2 heightened extracellular oxidation efficacy, promoting the desorption and removal of CBZ. The degradation of EPS prompted the transformation of bound water to free water, while the formation of larger channels drove the discharge of water. This work achieved the concept of treating waste with waste through using tea waste to treat sludge, meanwhile, can provide ideas for subsequent sludge harmless disposal.
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Affiliation(s)
- Wei Lin
- State Key Laboratory of Urban Water Resource and Environment (SKLUWRE), School of Environment, Harbin Institute of Technology, 73 Huanghe Road, Nangang District, 150090, Harbin, P.R. China
| | - Renglu Chen
- State Key Laboratory of Urban Water Resource and Environment (SKLUWRE), School of Environment, Harbin Institute of Technology, 73 Huanghe Road, Nangang District, 150090, Harbin, P.R. China
| | - Chuangxin Gong
- State Key Laboratory of Urban Water Resource and Environment (SKLUWRE), School of Environment, Harbin Institute of Technology, 73 Huanghe Road, Nangang District, 150090, Harbin, P.R. China
| | - Peter Desmond
- Institute of Environmental Engineering, RWTH Aachen University, Aachen, Germany; Sustainability Division, College of Science and Engineering, Hamad Bin Khalifa University, Qatar Foundation, Doha, Qatar
| | - Xu He
- State Key Laboratory of Urban Water Resource and Environment (SKLUWRE), School of Environment, Harbin Institute of Technology, 73 Huanghe Road, Nangang District, 150090, Harbin, P.R. China
| | - Jun Nan
- State Key Laboratory of Urban Water Resource and Environment (SKLUWRE), School of Environment, Harbin Institute of Technology, 73 Huanghe Road, Nangang District, 150090, Harbin, P.R. China
| | - Guibai Li
- State Key Laboratory of Urban Water Resource and Environment (SKLUWRE), School of Environment, Harbin Institute of Technology, 73 Huanghe Road, Nangang District, 150090, Harbin, P.R. China
| | - Jun Ma
- State Key Laboratory of Urban Water Resource and Environment (SKLUWRE), School of Environment, Harbin Institute of Technology, 73 Huanghe Road, Nangang District, 150090, Harbin, P.R. China
| | - An Ding
- State Key Laboratory of Urban Water Resource and Environment (SKLUWRE), School of Environment, Harbin Institute of Technology, 73 Huanghe Road, Nangang District, 150090, Harbin, P.R. China.
| | - Huu Hao Ngo
- Faculty of Engineering, University of Technology Sydney, P.O. Box 123, Broadway, Sydney, NSW 2007, Australia
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Jun BM, Chae SH, Kim D, Jung JY, Kim TJ, Nam SN, Yoon Y, Park C, Rho H. Adsorption of uranyl ion on hexagonal boron nitride for remediation of real U-contaminated soil and its interpretation using random forest. JOURNAL OF HAZARDOUS MATERIALS 2024; 469:134072. [PMID: 38522201 DOI: 10.1016/j.jhazmat.2024.134072] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/19/2024] [Revised: 03/09/2024] [Accepted: 03/16/2024] [Indexed: 03/26/2024]
Abstract
Acid leaching has been widely applied to treat contaminated soil, however, it contains several inorganic pollutants. The decommissioning of nuclear power plants introduces radioactive and soluble U(VI), a substance posing chemical toxicity to humans. Our investigation sought to ascertain the efficacy of hexagonal boron nitride (h-BN), an highly efficient adsorbent, in treating U(VI) in wastewater. The adsorption equilibrium of U(VI) by h-BN reached saturation within a mere 2 h. The adsorption of U(VI) by h-BN appears to be facilitated through electrostatic attraction, as evidenced by the observed impact of pH variations, acidic agents (i.e., HCl or H2SO4), and the presence of background ions on the adsorption performance. A reusability test demonstrated the successful completion of five cycles of adsorption/desorption, relying on the surface characteristics of h-BN as influenced by solution pH. Based on the experimental variables of initial U(VI) concentration, exposure time, temperature, pH, and the presence of background ions/organic matter, a feature importance analysis using random forest (RF) was carried out to evaluate the correlation between performances and conditions. To the best of our knowledge, this study is the first attempt to conduct the adsorption of U(VI) generated from real contaminated soil by h-BN, followed by interpretation of the correlation between performance and conditions using RF. Lastly, a. plausible adsorption mechanism between U(VI) and h-BN was explained based on the experimental results, characterizations, and a. comparison with previous adsorption studies on the removal of heavy metals by h-BN.
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Affiliation(s)
- Byung-Moon Jun
- Radwaste Management Center, Korea Atomic Energy Research Institute (KAERI), 111 Daedeok-Daero 989beon-gil, Yuseong-Gu, Daejeon 34057, Republic of Korea
| | - Sung Ho Chae
- Center for Water Cycle Research, Korea Institute of Science and Technology (KIST), Seoul 02792, Republic of Korea
| | - Deokhwan Kim
- Department of Environment Research, Korea Institute of Civil Engineering and Building Technology (KICT), 283 Goyang-Daero, Ilsanseo-Gu, Goyang-si, Gyeonggi-do 10223, Republic of Korea; Department of Civil and Environment Engineering, University of Science and Technology (UST), 217 Gajeong-Ro, Yuseong-Gu, Daejeon 34113, Republic of Korea
| | - Jun-Young Jung
- Radwaste Management Center, Korea Atomic Energy Research Institute (KAERI), 111 Daedeok-Daero 989beon-gil, Yuseong-Gu, Daejeon 34057, Republic of Korea
| | - Tack-Jin Kim
- Radwaste Management Center, Korea Atomic Energy Research Institute (KAERI), 111 Daedeok-Daero 989beon-gil, Yuseong-Gu, Daejeon 34057, Republic of Korea
| | - Seong-Nam Nam
- Department of Chemical and Environmental Science, Korea Army Academy, Yeong-Cheon 495 Hoguk-ro, Gokyeong-myeon, Yeongcheon-si, Gyeongsangbuk-do, Republic of Korea
| | - Yeomin Yoon
- Department of Environmental Science and Engineering, Ewha Womans University, 52 Ewhayeodae-gil, Seodaemun-gu, Seoul 03760, Republic of Korea
| | - Chanhyuk Park
- Department of Environmental Science and Engineering, Ewha Womans University, 52 Ewhayeodae-gil, Seodaemun-gu, Seoul 03760, Republic of Korea
| | - Hojung Rho
- Department of Environment Research, Korea Institute of Civil Engineering and Building Technology (KICT), 283 Goyang-Daero, Ilsanseo-Gu, Goyang-si, Gyeonggi-do 10223, Republic of Korea; Department of Civil and Environment Engineering, University of Science and Technology (UST), 217 Gajeong-Ro, Yuseong-Gu, Daejeon 34113, Republic of Korea.
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Huan CA, Wang Q, Li X, Du C, Meng Q, Kang X, Liu W. Soluble carbon source recovery using preconditioning coagulants for applicable short-term fermentation of waste activated sludge in WWTPs. ENVIRONMENTAL RESEARCH 2024; 248:118409. [PMID: 38311203 DOI: 10.1016/j.envres.2024.118409] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/21/2023] [Revised: 01/28/2024] [Accepted: 02/01/2024] [Indexed: 02/09/2024]
Abstract
A huge production of waste activated sludge (WAS) has been a burden for wastewater treatment plants (WWTPs) with high disposal cost and little benefit back to wastewater purification. The short-chain fatty acids (SCFAs) produced by a short-term acidogenic fermentation of WAS before methane production have been proven to be a high-quality carbon source available for microbial denitrification process. The dual purpose of full recovery of fermentation liquid products and facilitating disposal of residual solid waste necessitate an efficient solid-liquid separation process of short-term fermentation liquid. The transformation and loss of various soluble carbon sources between solid and liquid are very important issues for carbon recovery efficiency when combining short-term fermentation and sludge dewatering in WWTPs. Here we testified the three conventional preconditioning coagulants, Polyferric Sulfate (PFS), Poly Aluminum Chloride (PAC) and Polyacrylamide (PAM), to improve the efficiency of subsequent solid-liquid separation. The results show that conversion yield of SCFAs in the liquid phase of sludge after short-term fermentation was 195 mg COD/g VSS, when using the coagulants PFS, PAC, and PAM for recovery, the recovery ratio was 79.5%, 82.0%, and 85.9%, respectively, while the dewaterability could be improved after preconditioning short-term fermentation sludge. The complexation of Al3+/Fe3+ in metal coagulants with carboxyl groups of SCFA demonstrated by Density Functional Theory calculation led to small part of soluble carbons co-migration to the solid phase, mainly a loss of high molecular weight organic compounds (carbohydrate, proteins, humic acids), while the application of PAM had little impact on carbon recovery. Economic calculations further showed PAM preconditioning short-term fermentation liquid of WAS could achieve higher recovery benefits.
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Affiliation(s)
- Chang-An Huan
- State Key Laboratory of Urban Water Resource and Environment, School of Civil and Environmental Engineering, Harbin Institute of Technology Shenzhen, Shenzhen, 518055, China
| | - Qiandi Wang
- CAS Key Laboratory of Environmental Biotechnology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, China
| | - Xiqi Li
- State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, Harbin, 150090, China
| | - Cong Du
- Shenzhen Academy of Environmental Sciences, Shenzhen Ecological Environment Bureau, Shenzhen, 518022, China.
| | - Qingjie Meng
- Shenzhen Shenshui Water Resources Consulting Co., Ltd., Shenzhen, 518004, China
| | - Xu Kang
- Shenzhen Shenshui Water Resources Consulting Co., Ltd., Shenzhen, 518004, China
| | - Wenzong Liu
- State Key Laboratory of Urban Water Resource and Environment, School of Civil and Environmental Engineering, Harbin Institute of Technology Shenzhen, Shenzhen, 518055, China.
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Wang B, Wang J, Hu Z, Zhu AL, Shen X, Cao X, Wen JL, Yuan TQ. Harnessing Renewable Lignocellulosic Potential for Sustainable Wastewater Purification. RESEARCH (WASHINGTON, D.C.) 2024; 7:0347. [PMID: 38576863 PMCID: PMC10993153 DOI: 10.34133/research.0347] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/11/2024] [Accepted: 03/07/2024] [Indexed: 04/06/2024]
Abstract
Utilizing renewable lignocellulosic resources for wastewater remediation is crucial to achieving sustainable social development. However, the resulting by-products and the synthetic process characterized by complexity, high cost, and environmental pollution limit the further development of lignocellulose-based materials. Here, we developed a sustainable strategy that involved a new functional deep eutectic solvent (DES) to deconstruct industrial xylose residue into cellulose-rich residue with carboxyl groups, lignin with carboxyl and quaternary ammonium salt groups, and DES effluent rich in lignin fragments. Subsequently, these fractions equipped with customized functionality were used to produce efficient wastewater remediation materials in cost-effective and environmentally sound manners, namely, photocatalyst prepared by carboxyl-modified cellulose residue, biochar-based adsorbent originated from modified lignin, and flocculant synthesized by self-catalytic in situ copolymerization of residual DES effluent at room temperature. Under the no-waste principle, this strategy upgraded the whole components of waste lignocellulose into high-value-added wastewater remediation materials with excellent universality. These materials in coordination with each other can stepwise purify high-hazardous mineral processing wastewater into drinkable water, including the removal of 99.81% of suspended solids, almost all various heavy metal ions, and 97.09% chemical oxygen demand, respectively. This work provided promising solutions and blueprints for lignocellulosic resources to alleviate water shortages while also advancing the global goal of carbon neutrality.
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Affiliation(s)
- Bin Wang
- State Key Laboratory of Efficient Production of Forest Resources,
Beijing Forestry University, Beijing 100083, China
- Beijing Key Laboratory of Lignocellulosic Chemistry,
Beijing Forestry University, Beijing 100083, China
| | - Jiaming Wang
- State Key Laboratory of Efficient Production of Forest Resources,
Beijing Forestry University, Beijing 100083, China
- Beijing Key Laboratory of Lignocellulosic Chemistry,
Beijing Forestry University, Beijing 100083, China
| | - Zhaohui Hu
- State Key Laboratory of Efficient Production of Forest Resources,
Beijing Forestry University, Beijing 100083, China
- Beijing Key Laboratory of Lignocellulosic Chemistry,
Beijing Forestry University, Beijing 100083, China
| | - An-Ling Zhu
- Hunan Nonferrous Metals Research Institute Co. Ltd., Changsha 410000, China
| | - Xiaojun Shen
- State Key Laboratory of Efficient Production of Forest Resources,
Beijing Forestry University, Beijing 100083, China
- Beijing Key Laboratory of Lignocellulosic Chemistry,
Beijing Forestry University, Beijing 100083, China
| | - Xuefei Cao
- State Key Laboratory of Efficient Production of Forest Resources,
Beijing Forestry University, Beijing 100083, China
- Beijing Key Laboratory of Lignocellulosic Chemistry,
Beijing Forestry University, Beijing 100083, China
| | - Jia-Long Wen
- State Key Laboratory of Efficient Production of Forest Resources,
Beijing Forestry University, Beijing 100083, China
- Beijing Key Laboratory of Lignocellulosic Chemistry,
Beijing Forestry University, Beijing 100083, China
| | - Tong-Qi Yuan
- State Key Laboratory of Efficient Production of Forest Resources,
Beijing Forestry University, Beijing 100083, China
- Beijing Key Laboratory of Lignocellulosic Chemistry,
Beijing Forestry University, Beijing 100083, China
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21
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Abdeljelil N, Ben Miloud Yahia N, Landoulsi A, Chatti A, Wattiez R, Gillan D, Van Houdt R. Proteomic and morphological insights into the exposure of Cupriavidus metallidurans CH34 planktonic cells and biofilms to aluminium. JOURNAL OF HAZARDOUS MATERIALS 2024; 465:133403. [PMID: 38215523 DOI: 10.1016/j.jhazmat.2023.133403] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/10/2023] [Revised: 12/15/2023] [Accepted: 12/27/2023] [Indexed: 01/14/2024]
Abstract
Aluminium (Al) is one of the most popular materials for industrial and domestic use. Nevertheless, research has proven that this metal can be toxic to most organisms. This light metal has no known biological function and to date very few aluminium-specific biological pathways have been identified. In addition, information about the impact of this metal on microbial life is scarce. Here, we aimed to study the effect of aluminium on the metal-resistant soil bacterium Cupriavidus metallidurans CH34 in different growth modes, i.e. planktonic cells, adhered cells and mature biofilms. Our results indicated that despite a significant tolerance to aluminium (minimal inhibitory concentration of 6.25 mM Al₂(SO₄)₃.18H₂O), the exposure of C. metallidurans to a sub-inhibitory dose (0.78 mM) caused early oxidative stress and an increase in hydrolytic activity. Changes in the outer membrane surface of planktonic cells were observed, in addition to a rapid disruption of mature biofilms. On protein level, aluminium exposure increased the expression of proteins involved in metabolic activity such as pyruvate kinase, formate dehydrogenase and poly(3-hydroxybutyrate) polymerase, whereas proteins involved in chemotaxis, and the production and transport of iron scavenging siderophores were significantly downregulated.
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Affiliation(s)
- Nissem Abdeljelil
- Proteomics and Microbiology Lab, Research Institute for Biosciences, Mons University, Mons, Belgium; Microbiology Unit, Belgian Nuclear Research Centre, SCK CEN, Mol, Belgium; Laboratory of Biochemistry and Molecular Biology, Faculty of Sciences of Bizerte, University of Carthage, Jarzouna, Tunisia
| | | | - Ahmed Landoulsi
- Laboratory of Biochemistry and Molecular Biology, Faculty of Sciences of Bizerte, University of Carthage, Jarzouna, Tunisia
| | - Abdelwaheb Chatti
- Laboratory of Biochemistry and Molecular Biology, Faculty of Sciences of Bizerte, University of Carthage, Jarzouna, Tunisia
| | - Ruddy Wattiez
- Proteomics and Microbiology Lab, Research Institute for Biosciences, Mons University, Mons, Belgium
| | - David Gillan
- Proteomics and Microbiology Lab, Research Institute for Biosciences, Mons University, Mons, Belgium
| | - Rob Van Houdt
- Microbiology Unit, Belgian Nuclear Research Centre, SCK CEN, Mol, Belgium.
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22
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Li X, Zhao Q, Li L, Mei W, Wang Z, Gao Q, Wang K, Zhou H, Wei L, Jiang J. Enhanced dewaterability of food waste digestate by biochar/potassium ferrate treatments: Performance and mechanisms. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2024; 354:120268. [PMID: 38364546 DOI: 10.1016/j.jenvman.2024.120268] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/04/2023] [Revised: 01/21/2024] [Accepted: 01/31/2024] [Indexed: 02/18/2024]
Abstract
The combined process of biochar (BC) and potassium ferrate (PF) offers a fascinating technique for efficient dewatering of digestate. However, the effects of BC/PF treatment on the dewaterability and mechanisms of FWD are still unknown. This study aimed to reveal the impact mechanisms of BC/PF treatment on digestate dewatering performance. Experimental results indicated that BC/PF treatment significantly enhanced the dewaterability of digestate, with the minimum specific resistance to filtration of (1.05 ± 0.02) × 1015 m·kg-1 and water content of 57.52 ± 0.51% being obtained at the concentrations of 0.018 g·g-1 total solid (TS) BC300 and 0.20 g·g-1 TS PF, which were 8.60% and 13.59% lower than PF treatment, respectively. BC/PF treatment proficiently reduced the fractal dimension, bound water content, apparent viscosity, and gel-like network structure strength of digestate, as well as increased the floc size and zeta potential of digestate. BC/PF treatment promoted the conversion of extracellular polymeric substances (EPS) fractions from inner EPS to soluble EPS, increased the fluorescence intensity of the dissolved compounds, and enhanced the hydrophobicity of proteins. Mechanisms investigations showed that BC/PF enhanced dewatering through non-reactive oxygen species pathways, i.e., via strong oxidative intermediate irons species Fe(V)/Fe(IV). BC/PF treatment enhanced the solubilization of nutrients, the inactivation of fecal coliforms, and the mitigation of heavy metal toxicity. The results suggested that BC/PF treatment is an effective digestate dewatering technology which can provide technological supports to the closed-loop treatment of FWD.
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Affiliation(s)
- Xinwen Li
- Department of Environment Science and Engineering, School of Environment, Harbin Institute of Technology, Harbin, 150090, China
| | - Qingliang Zhao
- Department of Environment Science and Engineering, School of Environment, Harbin Institute of Technology, Harbin, 150090, China; State Key Laboratory of Urban Water Resources and Environment (SKLUWRE), School of Environment, Harbin Institute of Technology, Harbin, 150090, China
| | - Lili Li
- Department of Environment Science and Engineering, School of Environment, Harbin Institute of Technology, Harbin, 150090, China.
| | - Wangyang Mei
- Department of Environment Science and Engineering, School of Environment, Harbin Institute of Technology, Harbin, 150090, China
| | - Zhaoxia Wang
- Department of Environment Science and Engineering, School of Environment, Harbin Institute of Technology, Harbin, 150090, China
| | - Qingwei Gao
- Department of Environment Science and Engineering, School of Environment, Harbin Institute of Technology, Harbin, 150090, China
| | - Kun Wang
- Department of Environment Science and Engineering, School of Environment, Harbin Institute of Technology, Harbin, 150090, China
| | - Huimin Zhou
- Department of Environment Science and Engineering, School of Environment, Harbin Institute of Technology, Harbin, 150090, China
| | - Liangliang Wei
- Department of Environment Science and Engineering, School of Environment, Harbin Institute of Technology, Harbin, 150090, China
| | - Junqiu Jiang
- Department of Environment Science and Engineering, School of Environment, Harbin Institute of Technology, Harbin, 150090, China; State Key Laboratory of Urban Water Resources and Environment (SKLUWRE), School of Environment, Harbin Institute of Technology, Harbin, 150090, China.
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23
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Solmaz A, Bölükbaşi ÖS, Sari ZA. Green industry work: production of FeCl 3 from iron and steel industry waste (mill scale) and its use in wastewater treatment. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2024; 31:19795-19814. [PMID: 38367113 PMCID: PMC10927800 DOI: 10.1007/s11356-024-32451-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/20/2023] [Accepted: 02/08/2024] [Indexed: 02/19/2024]
Abstract
Mill scale (MS) is considered to be a significant metallurgical waste, but there is no economical method yet to utilize its metal content. In this study, which covers various processes in several stages, the solution of iron in MS, which is the Iron and Steel Industry (I&SI) waste, as FeCl3 (MS-FeCl3) in the thermoreactor in the presence of HCl, was investigated. In the next step, the conditions for using this solution as a coagulant in the treatment of I&SI wastewater were investigated using the jar test. The results of the treated water sample were compared by chemical oxygen demand (COD), total suspended solids (TSS), color, and turbidity analyses using commercial aluminum sulfate (Al2(SO4)3) and FeCl3 (C-FeCl3). Additionally, heavy metal analyses were conducted, and the treatment performance of three coagulants was presented. Accordingly, while 2.0 mg/L anionic polyelectrolyte was consumed at a dosage of 4.05 mg/L Al2(SO4)3 at pH 7.0, 0.25 mg/L anionic polyelectrolyte was consumed at a dosage of 1.29 mg/L at pH 5.0 in the C-FeCl3 and MS-FeCl3 studies. Also, Fe, Cr, Mn, Ni, Zn, Cd, Hg, and Pb removal efficiencies were over 93.56% for all three coagulant usage cases. The results showed that the wastewater treatment performance of MS-FeCl3 by the recycling of MS, which is an I&SI waste, was at the same level as C-FeCl3. Thus, thanks to recycling, waste scale can be used as an alternative to commercial products for green production.
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Affiliation(s)
- Alper Solmaz
- Department of Environmental Protection and Control-Iskenderun Vocational School of Higher Education, Iskenderun Technical University, Hatay, Turkey.
| | - Ömer Saltuk Bölükbaşi
- Department of Metallurgy and Materials Engineering, Faculty of Engineering and Natural Sciences, Iskenderun Technical University, 31200, Hatay, Turkey
| | - Zeynel Abidin Sari
- Department of Metallurgy-Iskenderun Vocational School of Higher Education, Iskenderun Technical University, Hatay, Turkey
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24
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Zhao C, Huang J, Yang Z, Huang Z, Li C, Li H, Wu Z, Zhang X, Qin X, Yao S, Ruan M. An energy-efficient solution to sludge drying and combustion process through Camellia oleifera shells amended foaming. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2024; 354:120400. [PMID: 38417358 DOI: 10.1016/j.jenvman.2024.120400] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/27/2023] [Revised: 01/21/2024] [Accepted: 02/13/2024] [Indexed: 03/01/2024]
Abstract
Foaming pretreatment has been proven effective in promoting sludge drying, however, the variation in sludge properties significantly influences the foaming efficiency. Inspired by foam stabilizer of solid particles, Camellia oleifera shells (COS) was screened out from various biomasses as an additive incorporated with the CaO for promoting the sludge foaming. For the introduction of COS, this study analyzed the drying behaviors of foamed sludge, quantified the surface cracks information, characterized the combustion performance, and evaluated the energy consumption. The results indicated that 46.72-50.10% of time could be saved in foaming the sludge to 0.70 g/mL by addition of 3.0 wt% COS. Compared with the original sludge (OS), the 0.70 g/mL foamed sludge saved 47.43% of time for sludge drying at 80 °C, and this value further increased to 53.14% with 3.0 wt% COS addition. Combining the multifractal spectra and drying kinetics analysis, the foaming promoted the formation of complex surface cracks in the warm-up period, while COS further improved the complexity of cracks in the constant rate period, and the shrinkage of isolated sludge blocks in the falling rate period, thus enhanced the moisture diffusion and heat transfer. Furthermore, the appropriate porous structure and additional volatile matters promoted the combustion performance. The 0.90 g/mL foamed sludge with COS presented the lowest activation energy of 180.362 kJ/mol in combustion. Overall, compared with OS, the 0.70 g/mL foamed sludge with COS saved 40.65% energy consumption during the foaming, drying and combustion processes, providing an energy-efficient solution for the sludge treatment and disposal.
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Affiliation(s)
- Cheng Zhao
- School of Energy and Power Engineering, Changsha University of Science & Technology, Changsha, 410076, PR China; State Key Laboratory of Utilization of Woody Oil Resource, Hunan Academy of Forestry, Changsha, Hunan, 410004, PR China
| | - Jing Huang
- State Key Laboratory of Utilization of Woody Oil Resource, Hunan Academy of Forestry, Changsha, Hunan, 410004, PR China
| | - Zhaohui Yang
- College of Environmental Science and Engineering, Hunan University, Changsha, 410082, PR China
| | - Zhongliang Huang
- State Key Laboratory of Utilization of Woody Oil Resource, Hunan Academy of Forestry, Changsha, Hunan, 410004, PR China
| | - Changzhu Li
- State Key Laboratory of Utilization of Woody Oil Resource, Hunan Academy of Forestry, Changsha, Hunan, 410004, PR China
| | - Hui Li
- State Key Laboratory of Utilization of Woody Oil Resource, Hunan Academy of Forestry, Changsha, Hunan, 410004, PR China
| | - Zijian Wu
- State Key Laboratory of Utilization of Woody Oil Resource, Hunan Academy of Forestry, Changsha, Hunan, 410004, PR China
| | - Xuan Zhang
- State Key Laboratory of Utilization of Woody Oil Resource, Hunan Academy of Forestry, Changsha, Hunan, 410004, PR China
| | - Xiaoli Qin
- State Key Laboratory of Utilization of Woody Oil Resource, Hunan Academy of Forestry, Changsha, Hunan, 410004, PR China
| | - Shirong Yao
- School of Energy and Power Engineering, Changsha University of Science & Technology, Changsha, 410076, PR China; State Key Laboratory of Utilization of Woody Oil Resource, Hunan Academy of Forestry, Changsha, Hunan, 410004, PR China
| | - Min Ruan
- School of Energy and Power Engineering, Changsha University of Science & Technology, Changsha, 410076, PR China.
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25
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Chopade G, Devatha CP. Experimental investigation on sludge conditioning and dewatering using an agricultural biomass coupled with resource recovery. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2024; 352:120098. [PMID: 38266529 DOI: 10.1016/j.jenvman.2024.120098] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/10/2023] [Revised: 01/08/2024] [Accepted: 01/08/2024] [Indexed: 01/26/2024]
Abstract
In this study, the effect of modified areca husk fibre biochar (MAFB-AlCl3) on dairy sludge conditioning and dewatering along with raw and modified coconut shell biochar (MCSB-FeCl3) was investigated. Further, MgO impregnated biochars of areca husk fibre and coconut shells was carried out to evaluate the performance on phosphate recovery from the diary sludge. The enhancement in sludge dewatering with MAFB-AlCl3 were evaluated experimentally and significant reduction of capillary suction time (CST) (51.6 %), moisture content (18%), zeta potential (1.3 mV) and increased settleability (32.7%) were observed. The sludge conditioning parameters namely dosage (% of dry solids (DS)), rapid mixing time (RMT), slow mixing time (SMT) were optimized by response surface methodology for the modified biochars. Optimum CST (31.51 s) was obtained at dosage (50 % of DS), RMT (9.89 min) and SMT (17.23 min). Results of batch study for phosphate recovery by MgO impregnated biochars (MgB) was found to be 96.6 % and 100 % by MgB of areca husk fibre (MgAFB) and coconut shells (MgCSB) respectively. The morphological characteristics and elemental distribution using field emission scanning electron microscopy (FE-SEM) & energy dispersive X-ray spectroscopy (EDS) reveals the structural change in the sludge particles for the modified biochars as well as for sludge. Hence MAFB-AlCl3, MgAFB and MgCSB is proved to be suitable and an effective candidate for sludge conditioning and dewatering coupled with phosphate recovery in handling the diary sludge.
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Affiliation(s)
- Gaurao Chopade
- Department of Civil Engineering, National Institute of Technology, Karnataka, Surathkal, Mangalore, 575025, Karnataka, India.
| | - C P Devatha
- Department of Civil Engineering, National Institute of Technology, Karnataka, Surathkal, Mangalore, 575025, Karnataka, India.
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26
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Hou J, Hong C, Ling W, Hu J, Feng W, Xing Y, Wang Y, Zhao C, Feng L. Research progress in improving sludge dewaterability: sludge characteristics, chemical conditioning and influencing factors. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2024; 351:119863. [PMID: 38141343 DOI: 10.1016/j.jenvman.2023.119863] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/11/2023] [Revised: 11/29/2023] [Accepted: 12/12/2023] [Indexed: 12/25/2023]
Abstract
Sludge from wastewater treatment processes with high water content and large volume has become an inevitable issue in environmental management. Due to the challenging dewatering properties of sludge, current mechanical dewatering methods are no longer sufficient to meet the escalating water content standards of sludge. This paper summarizes the characteristics of various sludge and raises reasons for the their dewaterability differences. Affected by extracellular polymeric substances, biological sludge is hydrophilic and negatively charged, which limits the dewatering degree. The rheological properties, flocs, ionic composition, and solid phase concentration of the sludge also influence the dewatering to some extent. For these factors, the chemical conditioning measures with simple operation and excellent effect improve its dewaterability, which mainly include flocculation/coagulation, acid/alkali treatment, advanced oxidation, surfactant treatment and combined treatment. There is a growing necessity to explore the development of new chemical conditioning agents, even though traditional agents continue to remain widely used. However, the development of these new agents should prioritize finding a balance between various factors such as efficiency, effectiveness, ease of operation, environmental safety, and cost-effectiveness. Electrochemical dewatering enhances solid-liquid separation, and its coupling with chemical conditioning is also an excellent means to further reduce water content. In addition, the improvement of press filter is an effective way, which is influenced by pressure, processing time, sludge cake thickness and pore structure, filter media etc. In general, it is essential to develop new conditioning agents and enhance mechanical filtration press technology based on a thorough understanding of various sludge properties. Concurrently, an in-depth study of the principles of mechanical pressure filtration will contribute to establishing a theoretical foundation for effective deep sludge dewatering and propel further advancements in this field.
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Affiliation(s)
- Jiachen Hou
- School of Energy and Environmental Engineering, University of Science and Technology Beijing, Beijing, 100083, China
| | - Chen Hong
- School of Energy and Environmental Engineering, University of Science and Technology Beijing, Beijing, 100083, China; Beijing Key Laboratory of Resource-oriented Treatment of Industrial Pollutants, University of Science and Technology Beijing, Beijing, 100083, China.
| | - Wei Ling
- School of Energy and Environmental Engineering, University of Science and Technology Beijing, Beijing, 100083, China
| | - Jiashuo Hu
- School of Energy and Environmental Engineering, University of Science and Technology Beijing, Beijing, 100083, China
| | - Weibo Feng
- School of Energy and Environmental Engineering, University of Science and Technology Beijing, Beijing, 100083, China
| | - Yi Xing
- School of Energy and Environmental Engineering, University of Science and Technology Beijing, Beijing, 100083, China; Beijing Key Laboratory of Resource-oriented Treatment of Industrial Pollutants, University of Science and Technology Beijing, Beijing, 100083, China
| | - Yijie Wang
- School of Energy and Environmental Engineering, University of Science and Technology Beijing, Beijing, 100083, China
| | - Chengwang Zhao
- School of Energy and Environmental Engineering, University of Science and Technology Beijing, Beijing, 100083, China
| | - Lihui Feng
- School of Energy and Environmental Engineering, University of Science and Technology Beijing, Beijing, 100083, China
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27
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Zhang K, Xie Y, Niu L, Huang X, Yu X, Feng M. Fe(IV)/Fe(V)-mediated polyferric sulfate/periodate system: A novel coagulant/oxidant strategy in promoting micropollutant abatement. JOURNAL OF HAZARDOUS MATERIALS 2024; 466:133614. [PMID: 38290329 DOI: 10.1016/j.jhazmat.2024.133614] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/13/2023] [Revised: 01/15/2024] [Accepted: 01/23/2024] [Indexed: 02/01/2024]
Abstract
Strategic modulation of the advanced oxidation processes for the selective oxidation of micropollutants has attracted accumulating attention in water decontamination. This study first reported the combination of the coagulant polyferric sulfate (PFS) and oxidant periodate (PI) to accomplish synergistic abatement of the antibiotic sulfamethoxazole (SMX). The oxidizing performance of SMX by this system was almost unaffected by coexisting water constituents, indicating the great promise of selective oxidation. Different from the current hydroxyl radicals (•OH)-mediated coagulant/oxidant systems (e.g., PFS/H2O2 and PFS/ozone), the dominance of high-valent Fe(IV)/Fe(V) intermediates was unambiguously verified in the PFS/PI treatment. The PFS colloids before and after the oxidation were characterized and the iron speciation was analyzed. The transformation of monomeric iron configurations (Fe(a)) to oligomeric iron configurations (Fe(b)) could maintain the homeostasis of surface-bound Fe(III) and Fe(II). The interaction mechanisms included the production of reactive species and dynamic reaction equilibrium for micropollutant degradation. Finally, the transformation pathways of SMX and carbamazepine (CMZ) in the PFS/PI system were postulated. Overall, this study provided a novel coagulant/oxidant strategy to achieve selective and sustainable water purification.
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Affiliation(s)
- Kaiting Zhang
- Fujian Key Laboratory of Coastal Pollution Prevention and Control, College of the Environment & Ecology, Xiamen University, Xiamen 361102, China
| | - Yuwei Xie
- Fujian Key Laboratory of Coastal Pollution Prevention and Control, College of the Environment & Ecology, Xiamen University, Xiamen 361102, China
| | - Lijun Niu
- Fujian Key Laboratory of Coastal Pollution Prevention and Control, College of the Environment & Ecology, Xiamen University, Xiamen 361102, China
| | - Xiangbin Huang
- Fujian Key Laboratory of Coastal Pollution Prevention and Control, College of the Environment & Ecology, Xiamen University, Xiamen 361102, China
| | - Xin Yu
- Fujian Key Laboratory of Coastal Pollution Prevention and Control, College of the Environment & Ecology, Xiamen University, Xiamen 361102, China
| | - Mingbao Feng
- Fujian Key Laboratory of Coastal Pollution Prevention and Control, College of the Environment & Ecology, Xiamen University, Xiamen 361102, China.
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28
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Lv L, Yang M, Liu W. Effects of organic matter and dewaterability changes on sludge calorific value during acid treatment. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2024; 31:2104-2116. [PMID: 38051485 DOI: 10.1007/s11356-023-30957-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/06/2023] [Accepted: 11/04/2023] [Indexed: 12/07/2023]
Abstract
Acid treatment can increase the sludge calorific value to some extent by separating inorganic elements. In order to determine the mechanism by which acidification affects the sludge calorific value from an organic perspective, we investigated the changes in organic matter and dewaterability under different pH conditions. The results of this study showed that acidification conditioning retained organic matter while removing a greater amount of inorganic elements. Furthermore, acid treatment significantly increased the zeta potential and particle size of sludge particles and facilitated the precipitation of biological organic components from the supernatant to the surface of sludge particles. Acid-treated sludge exhibited a lower moisture content and a higher proportion of organic matter, and sludge treated with H2SO4, HCl, and HNO3 exhibited respective increases in calorific values of 12.14%, 7.92%, and 8.01% under pH 2. The calorific value of the acid-treated sludge was higher, making it more suitable for subsequent incineration. The findings of this study serve as a reference and foundation for efficient sludge incineration.
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Affiliation(s)
- Lieyang Lv
- School of Environmental Science and Engineering, Sun Yat-Sen University, Guangzhou, 510006, People's Republic of China
- Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, Guangzhou, 510006, People's Republic of China
| | - Meiqi Yang
- School of Environmental Science and Engineering, Sun Yat-Sen University, Guangzhou, 510006, People's Republic of China
- Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, Guangzhou, 510006, People's Republic of China
| | - Wei Liu
- School of Environmental Science and Engineering, Sun Yat-Sen University, Guangzhou, 510006, People's Republic of China.
- Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, Guangzhou, 510006, People's Republic of China.
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29
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Zhang B, Tang X, Xu Q, Fan C, Gao Y, Li S, Wang M, Li C. Anionic polyacrylamide alleviates cadmium inhibition on anaerobic digestion of waste activated sludge. ENVIRONMENTAL SCIENCE AND ECOTECHNOLOGY 2024; 17:100306. [PMID: 37701857 PMCID: PMC10494310 DOI: 10.1016/j.ese.2023.100306] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/14/2023] [Revised: 07/17/2023] [Accepted: 07/22/2023] [Indexed: 09/14/2023]
Abstract
The uncontrolled discharge of industrial wastewater leads to a significant cadmium (Cd) accumulation in waste activated sludge (WAS), posing a serious threat to the steady operation of the anaerobic digestion (AD) system in wastewater treatment plants (WWTPs). Therefore, developing a viable approach to cope with the adverse effects of high-concentration Cd on the AD system is urgently required. This study aims to investigate the potential of using anionic polyacrylamide (APAM), a commonly used agent in WWTPs, to mitigate the adverse effects of Cd in a toxic amount (i.e., 5.0 mg per g total suspended solids (TSS)) on AD of WAS. The results showed that the effectiveness of higher APAM on Cd toxicity alleviation was less than that of lower APAM at the studied level (i.e., the effectiveness order was 1.5 mg APAM per g TSS > 3.0 mg APAM per g TSS > 6.0 mg APAM per g TSS). The moderate supplement of APAM (i.e., 1.5 mg per g TSS) recovered the accumulative methane yield from 190.5 ± 3.6 to 228.9 ± 4.1 mL per g volatile solids by promoting solubilization, hydrolysis, and acidification processes related to methane production. The application of APAM also increased the abundance of key microbes in the AD system, especially Methanolinea among methanogens and Caldilineaceae among hydrolyzers. Furthermore, APAM facilitated the key enzyme activities involved in AD processes and reduced reactive oxygen species (induced by Cd) production via adsorption/enmeshment of Cd by APAM. These findings demonstrate the feasibility of using moderate APAM to mitigate Cd toxicity during AD, providing a promising solution for controlling Cd or other heavy metal toxicity in WWTPs.
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Affiliation(s)
- Baowei Zhang
- College of Environmental Science and Engineering, Hunan University and Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Changsha, 410082, PR China
| | - Xiang Tang
- College of Environmental Science and Engineering, Hunan University and Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Changsha, 410082, PR China
| | - Qiuxiang Xu
- College of Environmental Science and Engineering, Hunan University and Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Changsha, 410082, PR China
| | - Changzheng Fan
- College of Environmental Science and Engineering, Hunan University and Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Changsha, 410082, PR China
| | - Yuying Gao
- College of Environmental Science and Engineering, Hunan University and Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Changsha, 410082, PR China
| | - Shuang Li
- College of Environmental Science and Engineering, Hunan University and Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Changsha, 410082, PR China
| | - Mier Wang
- College of Environmental Science and Engineering, Hunan University and Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Changsha, 410082, PR China
| | - Chao Li
- College of Environmental Science and Engineering, Hunan University and Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Changsha, 410082, PR China
- College of Mechanical & Electrical Engineering, Hunan Agricultural University, Changsha, 410128, PR China
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30
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Bao P, Du C, Li Y, Jiang H, Zhou L, Yu G, Sun S, Zhou L, Li X, Teng J, Wang X, Wang J. Application of skeleton builders to sludge dewatering and disposal: A critical review. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 906:167106. [PMID: 37717769 DOI: 10.1016/j.scitotenv.2023.167106] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/11/2023] [Revised: 09/13/2023] [Accepted: 09/13/2023] [Indexed: 09/19/2023]
Abstract
With the development of cities and population, the production of sludge is increasing annually. It has become an unavoidable challenge to achieve sludge dewatering and disposal by a cost-effective, efficient and safe process. In this work, firstly, the factors limiting sludge dewatering are reviewed in terms of moisture distribution, sludge concentration, organic matter content, electronegativity, floc strength, and extracellular polymers (EPS). Subsequently, focusing on the dewatering technology about the skeleton builder, the recent progress of it is detailed in terms of mechanism, evaluation indicators, influencing factors, and technology coupling. In addition, the impact of skeleton builders on the sludge disposal stage is concluded. Finally, the challenges faced by sludge dewatering and skeleton builders are prospected. This review will provide some theoretical basis and technical guidance for subsequent experiments and practices regarding skeleton builders.
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Affiliation(s)
- Purui Bao
- School of Hydraulic and Environmental Engineering, Changsha University of Science and Technology, Changsha 410114, China
| | - Chunyan Du
- School of Hydraulic and Environmental Engineering, Changsha University of Science and Technology, Changsha 410114, China; Engineering Technology Research Center of Hunan Dongting Lake Flood Control and Water Resources Protection of Hunan Province, Hunan Water Resources and Hydropower Survey, Design, Planning and Research Co., Ltd, Changsha 410007, China; Engineering and Technical Center of Hunan Provincial Environmental Protection for River Lake Dredging Pollution Control, Changsha 410114, China.
| | - Yifu Li
- School of Hydraulic and Environmental Engineering, Changsha University of Science and Technology, Changsha 410114, China; Engineering and Technical Center of Hunan Provincial Environmental Protection for River Lake Dredging Pollution Control, Changsha 410114, China.
| | - Heng Jiang
- Engineering Technology Research Center of Hunan Dongting Lake Flood Control and Water Resources Protection of Hunan Province, Hunan Water Resources and Hydropower Survey, Design, Planning and Research Co., Ltd, Changsha 410007, China
| | - Lu Zhou
- School of Hydraulic and Environmental Engineering, Changsha University of Science and Technology, Changsha 410114, China; Engineering and Technical Center of Hunan Provincial Environmental Protection for River Lake Dredging Pollution Control, Changsha 410114, China
| | - Guanlong Yu
- School of Hydraulic and Environmental Engineering, Changsha University of Science and Technology, Changsha 410114, China; Engineering and Technical Center of Hunan Provincial Environmental Protection for River Lake Dredging Pollution Control, Changsha 410114, China
| | - Shiquan Sun
- School of Hydraulic and Environmental Engineering, Changsha University of Science and Technology, Changsha 410114, China; Engineering and Technical Center of Hunan Provincial Environmental Protection for River Lake Dredging Pollution Control, Changsha 410114, China
| | - Lean Zhou
- School of Hydraulic and Environmental Engineering, Changsha University of Science and Technology, Changsha 410114, China; Engineering and Technical Center of Hunan Provincial Environmental Protection for River Lake Dredging Pollution Control, Changsha 410114, China
| | - Xue Li
- School of Hydraulic and Environmental Engineering, Changsha University of Science and Technology, Changsha 410114, China
| | - Junyi Teng
- School of Hydraulic and Environmental Engineering, Changsha University of Science and Technology, Changsha 410114, China
| | - Xiaowen Wang
- School of Hydraulic and Environmental Engineering, Changsha University of Science and Technology, Changsha 410114, China
| | - Junchao Wang
- School of Hydraulic and Environmental Engineering, Changsha University of Science and Technology, Changsha 410114, China
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Reza T, Mohamad Riza ZH, Sheikh Abdullah SR, Abu Hasan H, Ismail N‘I, Othman AR. Microplastic Removal in Wastewater Treatment Plants (WWTPs) by Natural Coagulation: A Literature Review. TOXICS 2023; 12:12. [PMID: 38250968 PMCID: PMC10819662 DOI: 10.3390/toxics12010012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/20/2023] [Revised: 12/06/2023] [Accepted: 12/13/2023] [Indexed: 01/23/2024]
Abstract
Urban industrialization has caused a ubiquity of microplastics in the environment. A large percentage of plastic waste originated from Southeast Asian countries. Microplastics arising from the primary sources of personal care items and industrial uses and the fragmentation of larger plastics have recently garnered attention due to their ubiquity. Due to the rising level of plastic waste in the environment, the bioaccumulation and biomagnification of plastics threaten aquatic and human life. Wastewater treatment plant (WWTP) effluents are one of the major sources of these plastic fragments. WWTPs in Southeast Asia contribute largely to microplastic pollution in the marine environment, and thus, further technological improvements are required to ensure the complete and efficient removal of microplastics. Coagulation is a significant process in removing microplastics, and natural coagulants are far superior to their chemical equivalents due to their non-toxicity and cost-effectiveness. A focused literature search was conducted on journal repository platforms, mainly ScienceDirect and Elsevier, and on scientific databases such as Google Scholar using the keywords Wastewater Treatment Plant, Coagulation, Microplastics, Marine Environment and Southeast Asia. The contents and results of numerous papers and research articles were reviewed, and the relevant papers were selected. The relevant findings and research data are summarized in this paper. The paper reviews (1) natural coagulants for microplastic removal and their effectiveness in removing microplastics and (2) the potential use of natural coagulants in Southeast Asian wastewater treatment plants as the abundance of natural materials readily available in the region makes it a feasible option for microplastic removal.
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Affiliation(s)
- Taskeen Reza
- Department of Chemical and Process Engineering, Faculty of Engineering and Built Environment, Universiti Kebangsaan, Bandar Baru Bangi 43600, Selangor, Malaysia; (T.R.); (Z.H.M.R.); (S.R.S.A.); (H.A.H.); (N.‘I.I.)
| | - Zahratul Huda Mohamad Riza
- Department of Chemical and Process Engineering, Faculty of Engineering and Built Environment, Universiti Kebangsaan, Bandar Baru Bangi 43600, Selangor, Malaysia; (T.R.); (Z.H.M.R.); (S.R.S.A.); (H.A.H.); (N.‘I.I.)
| | - Siti Rozaimah Sheikh Abdullah
- Department of Chemical and Process Engineering, Faculty of Engineering and Built Environment, Universiti Kebangsaan, Bandar Baru Bangi 43600, Selangor, Malaysia; (T.R.); (Z.H.M.R.); (S.R.S.A.); (H.A.H.); (N.‘I.I.)
| | - Hassimi Abu Hasan
- Department of Chemical and Process Engineering, Faculty of Engineering and Built Environment, Universiti Kebangsaan, Bandar Baru Bangi 43600, Selangor, Malaysia; (T.R.); (Z.H.M.R.); (S.R.S.A.); (H.A.H.); (N.‘I.I.)
- Research Centre for Sustainable Process Technology, Faculty of Engineering and Built Environment, Universiti Kebangsaan, Bandar Baru Bangi 43600, Selangor, Malaysia
| | - Nur ‘Izzati Ismail
- Department of Chemical and Process Engineering, Faculty of Engineering and Built Environment, Universiti Kebangsaan, Bandar Baru Bangi 43600, Selangor, Malaysia; (T.R.); (Z.H.M.R.); (S.R.S.A.); (H.A.H.); (N.‘I.I.)
| | - Ahmad Razi Othman
- Department of Chemical and Process Engineering, Faculty of Engineering and Built Environment, Universiti Kebangsaan, Bandar Baru Bangi 43600, Selangor, Malaysia; (T.R.); (Z.H.M.R.); (S.R.S.A.); (H.A.H.); (N.‘I.I.)
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32
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Streicher M, Boyko V, Blanazs A. Ultra-High-Molecular-Weight, Narrow-Polydispersity Polyacrylamides Synthesized Using Photoiniferter Polymerization to Generate High-Performance Flocculants. ACS APPLIED MATERIALS & INTERFACES 2023; 15:59044-59054. [PMID: 38059923 DOI: 10.1021/acsami.3c14483] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/08/2023]
Abstract
Ultra-high-molecular-weight, water-soluble polyelectrolytes are commonly employed as flocculants for solid-liquid separation via colloidal destabilization, enabling the rapid and efficient removal of particulate matter from wastewater streams. A drive toward more sustainable and less polluting industrial practices, coupled with the desire to reduce freshwater usage and improve closed-loop systems, demands the development of flocculants with ever-higher dewatering dose performance. Herein, the use of trithiocarbonate-mediated reversible addition-fragmentation chain transfer (RAFT) polymerization under either blue LED (λmax = 470 nm) or UV (λmax = 365 nm) irradiation, known as photoiniferter polymerization, was successfully utilized to generate ultra-high-molecular-weight (Mn > 1,000,000 g mol-1) polyelectrolyte copolymer flocculants with narrow molecular weight distributions (Mw/Mn < 1.2). Cationic and anionic polyelectrolyte flocculants were synthesized containing various monomer compositions of acrylamide (AM), dimethylacrylamide (DMA), 3-(acryloyloxyethyll)trimethylammonium chloride (DMAEAq), 3-(acrylamidopropyl)trimethylammonium chloride (APTAC), sodium acrylate (NaAA), and sodium 2-(acrylamido)-2-methylpropylsulfonate (NaATBS) with high monomer conversion using simple experimental apparatus. The narrow molecular weight distribution cationic polyelectrolytes showed improved flocculation efficiency in the clarification of kaolin suspensions of up to 50% in comparison to a broad polydispersity (Mw/Mn > 5.0) commercial benchmark with an equivalent number average molecular weight. The improved performance of the narrow-polydispersity copolymers is attributed to the reduction in the content of the lower-molecular-weight polymer chains, which impart lower flocculation performance.
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Affiliation(s)
| | | | - Adam Blanazs
- BASF SE, Carl-Bosch-Straße 38, 67056 Ludwigshafen, Germany
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Wang S, Chen H. Enhanced dewaterability of sewage sludge by grafted cationic lignin-based flocculants. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 903:166958. [PMID: 37696410 DOI: 10.1016/j.scitotenv.2023.166958] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/21/2023] [Revised: 09/07/2023] [Accepted: 09/08/2023] [Indexed: 09/13/2023]
Abstract
Lignin-based flocculants are widely used for wastewater purification, but their application in sludge dewatering has not yet been documented. In this study, a novel cationic lignin-based flocculant named LS-g-CPA was prepared by grafting cationic polyacrylamide (CPA) synthesized from methacryloyloxy ethyltrimethyl ammonium chloride (DMC) and acrylamide (AM) onto sodium lignosulfonate (LS), and its roles and underlying mechanisms in sludge conditioning were investigated. The results showed that LS-g-CPA effectively improved the dewaterability of sludge, reducing the filtration resistance and filter cake moisture content of sludge from 0.61 ± 0.05 × 1012 m/kg to 0.14 ± 0.02 × 1012 m/kg and 85.64 ± 0.25 % to 76.84 ± 0.41 %, respectively. The dewatering performance of LS-g-CPA was positively correlated with the DMC/AM ratio. The quaternary ammonium groups brought by DMC disrupted the reticular structure of extracellular polymeric substances, exposing hydrophobic residues and releasing bound water. Nevertheless, the key to LS-g-CPA for improving sludge dewatering lies more in the amphoteric flocculant properties that enhance sludge flocculation and the octopus-type structure that provides good drainage channels. This study reveals that lignin-based flocculants are effective in improving the dewaterability of sludge, which provides direct evidence for their application in sludge dewatering.
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Affiliation(s)
- Shiqin Wang
- College of Environment and Resources, Xiangtan University, Xiangtan 411105, China
| | - Hongbo Chen
- College of Environment and Resources, Xiangtan University, Xiangtan 411105, China.
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34
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Shen S, Xia W, Luo Z, Pan Y, Hu P, Zhang L, Shi H, Yang H. Enhanced sludge dewaterability using a bifunctional hybrid coagulant. CHEMOSPHERE 2023; 344:140323. [PMID: 37777090 DOI: 10.1016/j.chemosphere.2023.140323] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/30/2023] [Revised: 08/16/2023] [Accepted: 09/27/2023] [Indexed: 10/02/2023]
Abstract
The combination of coagulation and addition of skeleton builder is a popular pretreatment method to improve the dewaterability of sludge. In this study, a novel bifunctional inorganic/organic hybrid coagulant (CS-Si@ATP) was designed and obtained by chemically coupling a cationic starch (CS) with a popular clay, that is, attapulgite (ATP), via a silane coupling agent (APTES) for one-step conditioning of sludge. CS-Si@ATP can evidently enhance the sludge dewatering performance compared with CS, ATP, and their simple combination due to the distinct dual functions of this hybrid coagulant. The tentacle-like cationic CS in CS-Si@ATP shows efficient charge neutralization effect to aggregate and precipitate the suspended solids for further formation of compact sludge cakes. Meanwhile, the internal ATP with a stable and rigid structure acts as the skeleton builder to notably improve the filterability and permeability of the sludge cakes. The synergistic effects of CS and ATP in CS-Si@ATP, i.e., the charge neutralization of CS and the skeleton construction of ATP, cause the evidently enhanced sludge dewaterability, with a filter cake moisture content approximately 78.30% after the mechanical dewatering at 0.05 MPa. In comparison with the traditional two-step combination process by separated addition of CS and ATP, the one-step addition of CS-Si@ATP can reduce the required ATP dose nearly an order of magnitude. Thus, CS-Si@ATP has the notable advantages of simple operation, efficient utilization of ATP and evident reduction of disposal cost. This study provides an environmentally friendly and cost-effective coagulant to further improve the dewaterability of sludge.
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Affiliation(s)
- Shaohang Shen
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing. 210023, PR China
| | - Wei Xia
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing. 210023, PR China
| | - Zhang Luo
- China Railway Engineering Services Co., Ltd., Chengdu, 610083, PR China
| | - Yu Pan
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing. 210023, PR China
| | - Pan Hu
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing. 210023, PR China
| | - Longguan Zhang
- China Railway Engineering Services Co., Ltd., Chengdu, 610083, PR China
| | - Hongtao Shi
- China Railway Engineering Services Co., Ltd., Chengdu, 610083, PR China
| | - Hu Yang
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing. 210023, PR China.
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Li T, Yang J, Zhou Y, Liu X, Luo Y, Fang D, Liang J, Li J, Zhou L. Promoting dewatering efficiency of sludge by bioleaching coupling chemical flocculation. ENVIRONMENTAL RESEARCH 2023; 237:117014. [PMID: 37652216 DOI: 10.1016/j.envres.2023.117014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/02/2023] [Revised: 08/14/2023] [Accepted: 08/27/2023] [Indexed: 09/02/2023]
Abstract
In recent years, bioleaching has emerged as a cost-effective technology for enhancing the dewaterability of sludge. However, the lengthy treatment time involved in sludge bioleaching processes limits daily treatment capacity for sludge. Here, a novel approach was developed through a short time of sludge bioleaching with A. ferrooxidans LX5 (A. f) and A. thiooxidans TS6 (A. t) followed by polyferric sulfate (PFS) flocculation (A. f + A. t + PFS). After 12.5 h of the A. f + A. t + PFS treatment (30% A. f, 10% A. t, 40 mg/g DS S0, 60 mg/g DS FeSO4•7H2O, and 120 mg/g DS PFS), the reduction efficiency of specific resistance to filtration (SRF) and sludge cake moisture content reached 94.0% and 11.6%, respectively, which were comparable to the results achieved through 24 h of completed bioleaching treatment. In pilot-scale applications, the mechanical dewatering performance was notably improved following A. f + A. t + PFS treatment, with the low moisture content of the treated sludge cake (∼59.2%). This study provides new insights into the A. f + A. t + PFS process and holds potential for developing efficient and promising sludge dewatering strategies in engineering application.
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Affiliation(s)
- Ting Li
- College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing, 210095, China
| | - Jiawei Yang
- College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing, 210095, China
| | - Yujun Zhou
- School of Environmental and Biological Engineering, Nanjing University of Science and Technology, Nanjing, 210094, China
| | - Xuan Liu
- College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing, 210095, China
| | - Yixin Luo
- College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing, 210095, China
| | - Di Fang
- College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing, 210095, China; Jiangsu Collaborative Innovation Center for Solid Organic Waste Resource Utilization, Nanjing, 210095, China
| | - Jianru Liang
- College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing, 210095, China; Jiangsu Collaborative Innovation Center for Solid Organic Waste Resource Utilization, Nanjing, 210095, China
| | - Jiansheng Li
- School of Environmental and Biological Engineering, Nanjing University of Science and Technology, Nanjing, 210094, China
| | - Lixiang Zhou
- College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing, 210095, China; Jiangsu Collaborative Innovation Center for Solid Organic Waste Resource Utilization, Nanjing, 210095, China.
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36
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Zhang YL, Zhang H, Liu WH, Sun P, Zheng SM, Gao YY, Zeng YP, Wang HF, Zeng RJ. Enhancing data reliability in quantitative characterization of moisture distribution in sludge using DSC: Impact of sample attributes and test parameters. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2023; 346:119017. [PMID: 37738720 DOI: 10.1016/j.jenvman.2023.119017] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/07/2023] [Revised: 09/02/2023] [Accepted: 09/14/2023] [Indexed: 09/24/2023]
Abstract
Exploring moisture distribution, especially bound water content, is vital for studying and applying sludge dewatering. The differential scanning calorimetry (DSC) method has been extensively utilized for the quantitative characterization of moisture distribution in sludge. However, this method has certain limitations, such as low reproducibility of results, leading to controversial parameter values in different papers and hindering result comparison. In this study, we investigated the influence of key sample attributes on measuring sludge bound water using the DSC method.The findings demonstrated that the moisture content and mass of sludge samples substantially influenced the reproducibility and stability of DSC test results. To ensure data reliability, the moisture content of the sludge sample should be minimized and kept below 84%, with the mass not exceeding 10 mg. Compared to the influence of sludge moisture content and sample mass, the heating rate (1⁓5 °C/min) minimally affected DSC test results. This study offers a comprehensive insight into how sample attributes and test parameters affect the quantitative characterization of bound water in sludge using the DSC method. Furthermore, practical strategies are presented to enhance the method's applicability in sludge bound water characterization.
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Affiliation(s)
- Ya-Li Zhang
- Fujian Provincial Key Laboratory of Soil Environmental Health and Regulation, College of Resources and Environment, Fujian Agriculture and Forestry University, Fuzhou, 350002, China
| | - Hao Zhang
- Fujian Provincial Key Laboratory of Soil Environmental Health and Regulation, College of Resources and Environment, Fujian Agriculture and Forestry University, Fuzhou, 350002, China
| | - Wen-Hui Liu
- Fujian Provincial Key Laboratory of Soil Environmental Health and Regulation, College of Resources and Environment, Fujian Agriculture and Forestry University, Fuzhou, 350002, China
| | - Ping Sun
- Fujian Provincial Key Laboratory of Soil Environmental Health and Regulation, College of Resources and Environment, Fujian Agriculture and Forestry University, Fuzhou, 350002, China
| | - Shao-Ming Zheng
- Fujian Fiber Inspection Center, Fujian Provincial Key Laboratory of Textiles Inspection Technology, Fuzhou, 350002, China
| | - Yun-Yan Gao
- Fujian Provincial Key Laboratory of Soil Environmental Health and Regulation, College of Resources and Environment, Fujian Agriculture and Forestry University, Fuzhou, 350002, China
| | - Yuan-Ping Zeng
- Fujian Provincial Key Laboratory of Soil Environmental Health and Regulation, College of Resources and Environment, Fujian Agriculture and Forestry University, Fuzhou, 350002, China
| | - Hou-Feng Wang
- Fujian Provincial Key Laboratory of Soil Environmental Health and Regulation, College of Resources and Environment, Fujian Agriculture and Forestry University, Fuzhou, 350002, China.
| | - Raymond Jianxiong Zeng
- Fujian Provincial Key Laboratory of Soil Environmental Health and Regulation, College of Resources and Environment, Fujian Agriculture and Forestry University, Fuzhou, 350002, China
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Nabwey HA, Tony MA. Dewatered Sludge Decorated with Nanoparticles for Alum Sludge Conditioning towards the Concept of "End-of-Waste". NANOMATERIALS (BASEL, SWITZERLAND) 2023; 13:2903. [PMID: 37947747 PMCID: PMC10647506 DOI: 10.3390/nano13212903] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/09/2023] [Revised: 11/02/2023] [Accepted: 11/03/2023] [Indexed: 11/12/2023]
Abstract
The circular economy concept is leading environmental engineering in the search for "End-of-Waste" criteria. Untreated waste residue results from drinking water treatment plants, causing severe environmental issues, and its reuse is essential. In this regard, this investigation introduces the beneficial reuses of alum sludge cake to close the loop between sludge waste generation and reuse. Considering alum sludge as a resource for dewatering instead of its categorization as a waste reflects an "End-of-Waste" approach. Alum sludge cake was thermally calcined at 400 °C and named thermally treated alum sludge cake (TAS-cake). In this study, TAS-cake decorated with magnetite with a percent weight of 5 to 1%, respectively, was labeled as TAS-cake@Fe-(5-1). X-ray diffraction (XRD) and morphologies were applied to characterize the hybrid composite. A Fenton-based hybrid composite was applied to extrude water from alum sludge for 7 min of conditioning time. Furthermore, the factorial design based on response surface methodology (RSM) was applied to optimize the operational variables. TAS-cake@Fe-(5-1) and hydrogen peroxide revealed 1.2 g/L and 740 mg/L doses at pH 3.0, showing pronounced performance and revealing the highest capillary suction time (CST) reduction, which reached 53%. A temperature increase also showed a pronounced enhancement effect on the sludge dewaterability that reached 72% when 55 °C was applied. Thus, such a novel conditioner is a promising candidate for alum sludge conditioning.
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Affiliation(s)
- Hossam A. Nabwey
- Department of Mathematics, College of Science and Humanities in Al-Kharj, Prince Sattam bin Abdulaziz University, Al-Kharj 11942, Saudi Arabia
- Basic Engineering Science Department, Faculty of Engineering, Menoufia University, Shebin El-Kom 32511, Egypt;
| | - Maha A. Tony
- Basic Engineering Science Department, Faculty of Engineering, Menoufia University, Shebin El-Kom 32511, Egypt;
- Advanced Materials/Solar Energy and Environmental Sustainability (AMSEES) Laboratory, Faculty of Engineering, Menoufia University, Shebin El-Kom 32511, Egypt
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38
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Dong Y, Shen Y, Yuan H, Ge D, Zhu N. Roles of catalytic ozonation by bimetallic Fe/Ce loading sludge-derived biochar in amelioration of sludge dewaterability: Performance and implementation mechanisms. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2023; 344:118430. [PMID: 37348300 DOI: 10.1016/j.jenvman.2023.118430] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/20/2023] [Revised: 06/02/2023] [Accepted: 06/14/2023] [Indexed: 06/24/2023]
Abstract
In this study, an environmentally friendly alternative was developed using catalytic ozonation by sludge-derived biochar loaded with bimetallic Fe/Ce (O3/SBC-FeCe) for enhanced sludge dewatering. The results indicated that the lowest capillary suction time (CST) of 20.9 s and water content of dewatered sludge cake (Wc) of 64.09% were achieved under the dosage of 40 mg O3/g dry solids (DS) and 0.4 g SBC-FeCe/g DS which were considered as the optimum condition. In view of excellent electron exchanging capacity of SBC-FeCe with rich Lewis acid sites and conversions of valence sates of Fe and Ce, more O3 were decomposed into reactive oxygen species under the catalytic action of SBC-FeCe, which strengthened oxidizing capacity. Enhanced oxidation rendered sludge cells inactivation and compact network structure rupture releasing intracellular water and organic substances. Subsequently, hydrophilic organic matters were attacked and eliminated lessening sludge viscosity and colloidal forces and intensifying hydrophobicity and flowability. In addition, changes of sludge morphology suggested that sludge roughness was alleviated, structural strength and compressibility were raised and porous and retiform structure was constructed providing channels for water outflow by adding skeleton builder of SBC-FeCe. Overall, the synergistic interaction of strengthened oxidation and skeleton construction improved sludge dewaterability.
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Affiliation(s)
- Yanting Dong
- Shanghai Engineering Research Center of Solid Waste Treatment and Resource Recovery, School of Environmental Science and Engineering, Shanghai Jiao Tong University, No.800 Dongchuan Road, Shanghai, 200240, China
| | - Yanwen Shen
- Shanghai Engineering Research Center of Solid Waste Treatment and Resource Recovery, School of Environmental Science and Engineering, Shanghai Jiao Tong University, No.800 Dongchuan Road, Shanghai, 200240, China
| | - Haiping Yuan
- Shanghai Engineering Research Center of Solid Waste Treatment and Resource Recovery, School of Environmental Science and Engineering, Shanghai Jiao Tong University, No.800 Dongchuan Road, Shanghai, 200240, China
| | - Dongdong Ge
- Shanghai Engineering Research Center of Solid Waste Treatment and Resource Recovery, School of Environmental Science and Engineering, Shanghai Jiao Tong University, No.800 Dongchuan Road, Shanghai, 200240, China
| | - Nanwen Zhu
- Shanghai Engineering Research Center of Solid Waste Treatment and Resource Recovery, School of Environmental Science and Engineering, Shanghai Jiao Tong University, No.800 Dongchuan Road, Shanghai, 200240, China.
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Zeng Y, Wang Z, Pan Z, Shen L, Teng J, Lin H, Zhang J. Novel thermodynamic mechanisms of co-conditioning with polymeric aluminum chloride and polyacrylamide for improved sludge dewatering: A paradigm shift in the field. ENVIRONMENTAL RESEARCH 2023; 234:116420. [PMID: 37327838 DOI: 10.1016/j.envres.2023.116420] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/30/2023] [Revised: 05/25/2023] [Accepted: 06/13/2023] [Indexed: 06/18/2023]
Abstract
This study investigated the combined effects of polymeric aluminum chloride (PAC) and polyacrylamide (PAM) on sludge dewatering, aiming to unveil underlying mechanisms. Co-conditioning with 15 mg g-1 PAC and 1 mg g-1 PAM achieved optimal dewatering, reducing specific filtration resistance (SFR) of co-conditioned sludge to 4.38 × 1012 m-1kg-1, a mere 48.1% of raw sludge's SFR. Compared with the CST of raw sludge (36.45 s), sludge sample can be significantly reduced to 17.7 s. Characterization tests showed enhanced neutralization and agglomeration in co-conditioned sludge. Theoretical calculations revealed elimination of interaction energy barriers between sludge particles post co-conditioning, converting sludge surface from hydrophilic (3.03 mJ m-2) to hydrophobic (-46.20 mJ m-2), facilitating spontaneous agglomeration. Findings explain improved dewatering performance. Based on Flory-Huggins lattice theory, connection between polymer structure and SFR was established. Raw sludge formation triggered significant change in chemical potential, increasing bound water retention capacity and SFR. In contrast, co-conditioned sludge exhibited thinnest gel layer, reducing SFR and significantly improving dewatering. These findings represent a paradigm shift, shedding new light on fundamental thermodynamic mechanisms of sludge dewatering with different chemical conditioning.
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Affiliation(s)
- Yansha Zeng
- College of Geography and Environmental Sciences, Zhejiang Normal University, Jinhua, 321004, China; Key Laboratory of Watershed Earth Surface Processes and Ecological Security, Zhejiang Normal University, Jinhua, 321004, China.
| | - Zhe Wang
- College of Geography and Environmental Sciences, Zhejiang Normal University, Jinhua, 321004, China; Key Laboratory of Watershed Earth Surface Processes and Ecological Security, Zhejiang Normal University, Jinhua, 321004, China.
| | - Zhenxiang Pan
- College of Geography and Environmental Sciences, Zhejiang Normal University, Jinhua, 321004, China; Key Laboratory of Watershed Earth Surface Processes and Ecological Security, Zhejiang Normal University, Jinhua, 321004, China.
| | - Liguo Shen
- College of Geography and Environmental Sciences, Zhejiang Normal University, Jinhua, 321004, China; Key Laboratory of Watershed Earth Surface Processes and Ecological Security, Zhejiang Normal University, Jinhua, 321004, China.
| | - Jiaheng Teng
- College of Geography and Environmental Sciences, Zhejiang Normal University, Jinhua, 321004, China; Key Laboratory of Watershed Earth Surface Processes and Ecological Security, Zhejiang Normal University, Jinhua, 321004, China.
| | - Hongjun Lin
- College of Geography and Environmental Sciences, Zhejiang Normal University, Jinhua, 321004, China; Key Laboratory of Watershed Earth Surface Processes and Ecological Security, Zhejiang Normal University, Jinhua, 321004, China.
| | - Jianzhen Zhang
- College of Geography and Environmental Sciences, Zhejiang Normal University, Jinhua, 321004, China; Key Laboratory of Watershed Earth Surface Processes and Ecological Security, Zhejiang Normal University, Jinhua, 321004, China.
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Wu B, Li H, Zhou K, Yu N, Xu Q, Chai X, Dai X. Crystallization-driven evolution of water occurrence states with implications on dewaterability improvement of waste-activated sludge. WATER RESEARCH 2023; 244:120496. [PMID: 37633208 DOI: 10.1016/j.watres.2023.120496] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/30/2023] [Revised: 07/25/2023] [Accepted: 08/16/2023] [Indexed: 08/28/2023]
Abstract
This study proposed to improve the dewaterability of waste-activated sludge (WAS) through crystallization-driven evolution of water occurrence states. Primarily, the feasibility of clathrate hydrate (i.e., CO2 hydrate) formation in WAS was examined. The thermodynamic analysis indicated that the CO2 hydrate formation with the excessive water in WAS followed pseudo-first-order kinetics, and fit of the data yielded a kobs value of 3.905 × 10-5 L∙mol-1∙s-1 for 274.15 K. With the water conversion efficiency of 100%, the crystallization-dissociation process of CO2 hydrate significantly improved the dewaterability of WAS in term of capillary suction time (CST) decreasing from 251.5 s to 57.4 s. Also, the relief of gas pressure can induce the hydrate dissociation, which creates a novel way to recycle CO2 gas and save the consumption of chemicals required by sludge dewatering process. Regarding the mechanism of hydrates-based sludge dewatering, the evolution of water occurrence state was investigated. The in-situ synchrotron X-ray computed microtomography visually analyzed the micro-scale porosity and interstitial water of WAS flocs. The model of three-dimensional pore structure was established and the porosity parameters of solid aggregates were determined. It was found that the volume of connected pores and the total pore volume fraction of solid compositions increased. But the mean volume and mean area of isolated pores simultaneously decreased by 14.6% and 12.4%, respectively, which meant that the steric hindrance caused by isolated pores was weakened due to the reduced solid-water contact area. In addition, the crystallization of water caused the reformation of conformation arrangement of vicinal water and solid molecules, which highly organized the water molecules into the crystal structure. Accordingly, an estimation method for vicinal water layer thickness was developed based on atom force microscope. The thickness of vicinal water layer was found to be reduced by 77.4% and the hydration repulsion among solid compositions was correspondingly weakened, which facilitated the aggregation of solid compositions, and the relatively separated hydrate phase and solid phase could be formed. All the above results open up a novel strategy for enhanced water-solid separation of WAS through the crystallization-driven evolution of water occurrence states. As distinguished from the conventional approaches, the hydrates-based sludge dewatering enhances the water-solid separation only with regulating the spatial arrangement of water-solid molecules, but without altering the chemical compositions. Thus, more chances can be created to increase the environmentally friendly attributes related to WAS dewatering.
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Affiliation(s)
- Boran Wu
- State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, 1239 Siping Road, Shanghai 200092, China; Shanghai Institute of Pollution Control and Ecological Security, Shanghai 200092, China
| | - Hewei Li
- State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, 1239 Siping Road, Shanghai 200092, China
| | - Kun Zhou
- Shanghai Municipal Engineering Design Institute (Group) Co., Ltd., 901 Zhongshan North 2nd Road, Shanghai 200092, China
| | - Ningrui Yu
- Shanghai Guohui Environmental Technology Co., Ltd., 169-39, Gaoguang Road, Shanghai 201702, China
| | - Qinqin Xu
- State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, 1239 Siping Road, Shanghai 200092, China
| | - Xiaoli Chai
- State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, 1239 Siping Road, Shanghai 200092, China; Shanghai Institute of Pollution Control and Ecological Security, Shanghai 200092, China.
| | - Xiaohu Dai
- State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, 1239 Siping Road, Shanghai 200092, China; Shanghai Institute of Pollution Control and Ecological Security, Shanghai 200092, China.
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Fan X, Wang Y, Zhang D, Zhang S, Liu C, Liu M. A comprehensive assessment on sludge conditioning by pyrite acid eluent-activated peroxymonosulfate based on dewaterability, heavy metals risk and ore recovery. WASTE MANAGEMENT (NEW YORK, N.Y.) 2023; 170:82-92. [PMID: 37556939 DOI: 10.1016/j.wasman.2023.08.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/17/2023] [Revised: 06/30/2023] [Accepted: 08/01/2023] [Indexed: 08/11/2023]
Abstract
Wastewater activated sludge (WAS) has poor dewaterability and contains heavy metals (HMs), limiting its land application. Therefore, in this study, a novel pyrite acid eluent-activated peroxymonosulfate (Fe2+pyrite/PMS) conditioning approach that can completely recover the residual pyrite and greatly reduce acid use was developed to improve WAS dewaterability, and the HMs chemical speciation and risks of conditioned WAS were assessed. Our results showed that under the optimized operational parameters, the capillary suction time (CST) and water content (Wc) of WAS decreased by 46.03% and 7.75%, respectively. Furthermore, during Fe2+pyrite/PMS conditioning processing, sulfate radical (SO4-) destroyed the extracellular polymeric substances (EPS) matrix, causing bound water release and the decrease of proteins/polysaccharides in outer layered EPS, even the decomposition of some protein-N in tightly bound EPS (TB-EPS) into inorganic-N. In addition, although the total concentration of HMs in the conditioned WAS matrix increased, the Ni concentration decreased in the solid fraction. Further, the risk assessment code (RAC) levels did not increase, and the eco-toxicity of Cr became weakened after Fe2+pyrite/PMS conditioning. However, after acid extraction, the pyrite residue had worsened recycle performance because the passivation layer contained S0/Sn2- on its surface, and no additional elements were detected in the pyrite residue, which had almost no effect on its further usage.
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Affiliation(s)
- Xiaoyang Fan
- Beijing Key Lab for Source Control Technology of Water Pollution, College of Environmental Science and Engineering, Beijing Forestry University, Beijing 100083, China; Engineering Research Center for Water Pollution Source Control & Eco-remediation, College of Environmental Science and Engineering, Beijing Forestry University, Beijing 100083, China.
| | - Yili Wang
- Beijing Key Lab for Source Control Technology of Water Pollution, College of Environmental Science and Engineering, Beijing Forestry University, Beijing 100083, China; Engineering Research Center for Water Pollution Source Control & Eco-remediation, College of Environmental Science and Engineering, Beijing Forestry University, Beijing 100083, China.
| | - Daxin Zhang
- Beijing Key Lab for Source Control Technology of Water Pollution, College of Environmental Science and Engineering, Beijing Forestry University, Beijing 100083, China; Engineering Research Center for Water Pollution Source Control & Eco-remediation, College of Environmental Science and Engineering, Beijing Forestry University, Beijing 100083, China.
| | - Shuting Zhang
- Beijing Key Lab for Source Control Technology of Water Pollution, College of Environmental Science and Engineering, Beijing Forestry University, Beijing 100083, China; Engineering Research Center for Water Pollution Source Control & Eco-remediation, College of Environmental Science and Engineering, Beijing Forestry University, Beijing 100083, China.
| | - Chenyang Liu
- Beijing Key Lab for Source Control Technology of Water Pollution, College of Environmental Science and Engineering, Beijing Forestry University, Beijing 100083, China; Engineering Research Center for Water Pollution Source Control & Eco-remediation, College of Environmental Science and Engineering, Beijing Forestry University, Beijing 100083, China.
| | - Meilin Liu
- Beijing Key Lab for Source Control Technology of Water Pollution, College of Environmental Science and Engineering, Beijing Forestry University, Beijing 100083, China; Engineering Research Center for Water Pollution Source Control & Eco-remediation, College of Environmental Science and Engineering, Beijing Forestry University, Beijing 100083, China.
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Li Y, Fu C, Cao X, Wang X, Wang N, Zheng M, Quan L, Lv J, Guo Z. Enhancement of sludge dewaterability by repeated inoculation of acidified sludge: Extracellular polymeric substances molecular structure and microbial community succession. CHEMOSPHERE 2023; 339:139714. [PMID: 37543234 DOI: 10.1016/j.chemosphere.2023.139714] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/09/2023] [Revised: 07/26/2023] [Accepted: 08/01/2023] [Indexed: 08/07/2023]
Abstract
Improving the dewatering performance of sewage sludge is of great scientific and engineering significance in the context of accelerated urbanization and increasingly strict environmental regulations. Acidified sludge (AS) can improve sludge dewatering performance, but the dewatering effect of repeated inoculation is unclear. The effects of long-term repeated inoculation of AS on the sludge dewaterability were investigated. The molecular structure and microbial community succession of extracellular polymeric substances (EPS) are emphasized. The results revealed that increasing the inoculation ratio of AS reduced the pH, absolute value of sludge zeta potential, and sludge particle size, and the decreasing trend was more evident with prolonging treatment time. Under the conditions of 30% and 50% AS inoculation, the dewatering performance of the sludge was significantly improved (p < 0.05). Compared with the raw sludge, the specific resistance of filtration (SRF) and capillary suction time of 30% inoculation were reduced by 64.3% and 50.1% after 30 cycles, respectively. Excluding loosely bound (LB)-EPS, soluble (S)-EPS and tightly bound (TB)-EPS exhibited a visible decrease, the protein in TB-EPS was significantly related to sludge dewaterability (p < 0.05). The fluorescent components of aromatic protein and fulvic acid-like substances in TB-EPS were significantly associated with SRF, with a correlation coefficient 0.99 (p < 0.05). Both the increase in the percentages of random coil and decrease in α-helix in TB-EPS contributed to improving dewaterability. Increasing Firmicutes and decreasing Chloroflexi levels improved the sludge dewatering capacity. Repeated inoculation did not disrupt the dewatering effect of AS rather increased the feasibility of the engineering application of AS. Considering the dewatering performance and cost synthetically, 30% AS inoculated ratio is feasible for practical applications.
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Affiliation(s)
- Yunbei Li
- School of Environment, Key Laboratory of Yellow River and Huai River Water Environment and Pollution Control, Ministry of Education, Henan Normal University, Xinxiang, 453007, China.
| | - Chunyan Fu
- School of Environment, Key Laboratory of Yellow River and Huai River Water Environment and Pollution Control, Ministry of Education, Henan Normal University, Xinxiang, 453007, China
| | - Xinyu Cao
- School of Environment, Key Laboratory of Yellow River and Huai River Water Environment and Pollution Control, Ministry of Education, Henan Normal University, Xinxiang, 453007, China
| | - Xin Wang
- School of Environment, Key Laboratory of Yellow River and Huai River Water Environment and Pollution Control, Ministry of Education, Henan Normal University, Xinxiang, 453007, China
| | - Ninghao Wang
- School of Environment, Key Laboratory of Yellow River and Huai River Water Environment and Pollution Control, Ministry of Education, Henan Normal University, Xinxiang, 453007, China
| | - Mengyu Zheng
- School of Environment, Key Laboratory of Yellow River and Huai River Water Environment and Pollution Control, Ministry of Education, Henan Normal University, Xinxiang, 453007, China
| | - Lijun Quan
- School of Environment, Key Laboratory of Yellow River and Huai River Water Environment and Pollution Control, Ministry of Education, Henan Normal University, Xinxiang, 453007, China
| | - Jinghua Lv
- School of Environment, Key Laboratory of Yellow River and Huai River Water Environment and Pollution Control, Ministry of Education, Henan Normal University, Xinxiang, 453007, China
| | - Zhensheng Guo
- School of Environment, Key Laboratory of Yellow River and Huai River Water Environment and Pollution Control, Ministry of Education, Henan Normal University, Xinxiang, 453007, China
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Yang B, Graham N, Liu P, Liu M, Gregory J, Yu W. Atomic-Level Structural Differences between Fe(III) Coprecipitates Generated by the Addition of Fe(III) Coagulants and by the Oxidation of Fe(II) Coagulants Determine Their Coagulation Behavior in Phosphate and DOM Removal. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2023; 57:12489-12500. [PMID: 37551789 DOI: 10.1021/acs.est.3c03463] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/09/2023]
Abstract
In situ Fe(III) coprecipitation from Fe2+ oxidation is a widespread phenomenon in natural environments and water treatment processes. Studies have shown the superiority of in situ Fe(III) (formed by in situ oxidation of a Fe(II) coagulant) over ex situ Fe(III) (using a Fe(III) coagulant directly) in coagulation, but the reasons remain unclear due to the uncertain nature of amorphous structures. Here, we utilized an in situ Fe(III) coagulation process, oxidizing the Fe(II) coagulant by potassium permanganate (KMnO4), to treat phosphate-containing surface water and analyzed differences between in situ and ex situ Fe(III) coagulation in phosphate removal, dissolved organic matter (DOM) removal, and floc growth. Compared to ex situ Fe(III), flocs formed by the natural oxidizing Fe2+ coagulant exhibited more effective phosphate removal. Furthermore, in situ Fe(III) formed through accelerated oxidation by KMnO4 demonstrated improved flocculation behavior and enhanced removal of specific types of DOM by forming a more stable structure while still maintaining effective phosphate removal. Fe K-edge extended X-ray absorption fine structure spectra (EXAFS) of the flocs explained their differences. A short-range ordered strengite-like structure (corner-linked PO4 tetrahedra to FeO6 octahedra) was the key to more effective phosphorus removal of in situ Fe(III) than ex situ Fe(III) and was well preserved when KMnO4 accelerated in situ Fe(III) formation. Conversely, KMnO4 significantly inhibited the edge and corner coordination between FeO6 octahedra and altered the floc-chain-forming behavior by accelerating hydrolysis, resulting in a more dispersed monomeric structure than ex situ Fe(III). This research provides an explanation for the superiority of in situ Fe(III) in phosphorus removal and highlights the importance of atomic-level structural differences between ex situ and in situ Fe(III) coprecipitates in water treatment.
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Affiliation(s)
- Bingqian Yang
- State Key Laboratory of Environmental Aquatic Chemistry, Key Laboratory of Drinking Water Science and Technology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, People's Republic of China
- University of Chinese Academy of Sciences, Beijing 100049, People's Republic of China
| | - Nigel Graham
- Department of Civil and Environmental Engineering, Imperial College London, South Kensington Campus, London SW7 2AZ, U.K
| | - Peng Liu
- School of Environmental Studies, China University of Geosciences, Wuhan 430074, China
| | - Mengjie Liu
- State Key Laboratory of Environmental Aquatic Chemistry, Key Laboratory of Drinking Water Science and Technology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, People's Republic of China
- University of Chinese Academy of Sciences, Beijing 100049, People's Republic of China
| | - John Gregory
- Department of Civil, Environmental and Geomatic Engineering, University College London, Gower Street, London WC1E 6BT, U.K
| | - Wenzheng Yu
- State Key Laboratory of Environmental Aquatic Chemistry, Key Laboratory of Drinking Water Science and Technology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, People's Republic of China
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Zhang Y, Liu J, Bao Y, Liu P, Wei J, Li X, Wang Q, Ge Z. Application of coffee ground-based skeleton builder with FeCl 3 for conditions of pre-dewatered sludge toward further deep dewatering. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2023:10.1007/s11356-023-29325-8. [PMID: 37608176 DOI: 10.1007/s11356-023-29325-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/16/2023] [Accepted: 08/09/2023] [Indexed: 08/24/2023]
Abstract
Skeleton builders are essential for achieving deep sludge dewatering. In this study, a novel spent coffee ground (SCG)-based skeleton builder was developed to attain deep sludge dewatering by combined conditioning with FeCl3, and possible mechanisms were examined. Through different surface analysis techniques, it was demonstrated that at a pyrolysis temperature of 300 °C, the spent coffee ground biochar (SCGB-300) has an intact pore structure, a rigid carbon skeleton, and large oxygen-containing functional groups, making it the best skeleton builder for sludge dewatering. When combined with FeCl3 for conditioning, the structure of SCGB-300 remained intact under high pressure and played important role. The rich porous structure facilitated water drainage. During the sludge conditioning, small amount of positive charge on the surface of SCGB-300 further increased the zeta potential of sludge through charge neutralization. At the same time, the adsorption of SCGB-300 removed viscous hydrophilic substances and further improved the dewatering performance. At an optimum dosage of 6% (dry solid, DS) FeCl3 and 30% SCGB-300 (DS), the moisture content of sludge was reduced from 85.47% to 63.35%, and the dewatering rate was increased from 46.08% to 70.03%. Therefore, SCGB is a promising skeleton builder for sludge conditioning and deep dewatering.
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Affiliation(s)
- Yixin Zhang
- National Engineering Laboratory for Advanced Municipal Wastewater Treatment and Reuse Technology, Beijing University of Technology|, Beijing, 100124, China
| | - Jibao Liu
- State Key Joint Laboratory of Environmental Simulation and Pollution Control, Research Center for Eco-environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, China
- Research Center for Eco-environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, China
| | - Yunfan Bao
- National Engineering Laboratory for Advanced Municipal Wastewater Treatment and Reuse Technology, Beijing University of Technology|, Beijing, 100124, China
| | - Pengyu Liu
- National Engineering Laboratory for Advanced Municipal Wastewater Treatment and Reuse Technology, Beijing University of Technology|, Beijing, 100124, China
| | - Jinyi Wei
- Research Center for Eco-environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, China
| | - Xueyi Li
- Beijing Capital Sludge Disposal Co. Ltd., Beijing, 100044, China
| | - Qiao Wang
- Beijing Capital Sludge Disposal Co. Ltd., Beijing, 100044, China
| | - Zheng Ge
- National Engineering Laboratory for Advanced Municipal Wastewater Treatment and Reuse Technology, Beijing University of Technology|, Beijing, 100124, China.
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Wu Z, Ji S, Li YY, Liu J. A review of iron use and recycling in municipal wastewater treatment plants and a novel applicable integrated process. BIORESOURCE TECHNOLOGY 2023; 379:129037. [PMID: 37037337 DOI: 10.1016/j.biortech.2023.129037] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/21/2023] [Revised: 04/03/2023] [Accepted: 04/07/2023] [Indexed: 05/03/2023]
Abstract
Chemical methods are expected to play an increasingly important role in carbon-neutral municipal wastewater treatment plants. This paper briefly summarises the enhancement effects of using iron salts in wastewater and sludge treatment processes. The costs and environmental concerns associated with the widespread use of iron salts have also been highlighted. Fortunately, the iron recovery from iron-rich sludge provides an opportunity to solve these problems. Existing iron recovery methods, including direct acidification and thermal treatment, are summarised and show that acidification treatment of FeS digestate from the anaerobic digestion-sulfate reduction process can increase the iron and sulphur recycling efficiency. Therefore, a novel applicable integrated process based on iron use and recycling is proposed, and it reduces the iron salts dosage to 4.2 mg/L and sludge amount by 80%. Current experimental research and economic analysis of iron recycling show that this process has broad application prospects in resource recovery and sludge reduction.
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Affiliation(s)
- Zhangsong Wu
- School of Environmental and Chemical Engineering, Shanghai University, 333 Nanchen Road, Shanghai 200444, China
| | - Shenghao Ji
- School of Environmental and Chemical Engineering, Shanghai University, 333 Nanchen Road, Shanghai 200444, China
| | - Yu-You Li
- Department of Civil and Environmental Engineering, Graduate School of Engineering, Tohoku University, 6-6-06 Aza, Aramaki, Aoba-ku, Sendai, Miyagi 980-8579, Japan
| | - Jianyong Liu
- School of Environmental and Chemical Engineering, Shanghai University, 333 Nanchen Road, Shanghai 200444, China.
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46
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Xu S, Shi J, Deng J, Sun H, Wu J, Ye Z. Flocculation and dewatering of the Kaolin slurry treated by single- and dual-polymer flocculants. CHEMOSPHERE 2023; 328:138445. [PMID: 36963584 DOI: 10.1016/j.chemosphere.2023.138445] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/03/2022] [Revised: 02/20/2023] [Accepted: 03/17/2023] [Indexed: 06/18/2023]
Abstract
To mitigate the sudden increase in the production of waste engineering slurry, predominantly composed of Kaolinite, this study investigated the flocculation and dewatering of Kaolin slurry treated with single- and dual-polymer flocculants. The influence of the flocculant type and dosage, under single- and dual-dose conditions, on slurry's sedimentation and the filtration characteristics, were thoroughly discussed. The results reveal that the adsorption bridging of the polymeric flocculant, resulting from hydrogen bonds, exerts a more significant effect than electrical neutralization on forming a large floc. Under single-dose conditions, nonionic polyacrylamides (NPAMs) with the strongest adsorption bridging leads to biggest flocs and the maximum settling rate of 21.55 mm/s. Under the dual-dose conditions of polymeric aluminium chloride (PAC) and PAM, the size of the slurry's floc decreases with an increase in PAC dosage. Nevertheless, the filtration performance of the slurry improves, with the lowest SRF value of the flocculated slurry being 1.58 × 1011 m/kg as 3‰ PAC and 3‰ NPAM is dosed. The improvement is explained by the micro-pore distribution of sludge. According to Mercury intrusion porosimetry (MIP) test, the slurry treated with the optimal dosage of dual-polymer flocculant exhibits the greatest sludge pore size and connected porosity (with a maximum value of 20.99%). Furthermore, the study discusses and compares the flocculation mechanism of single- and dual-polymer flocculants. The obtained results provide guidance for selecting appropriate flocculants for dewatering inorganic slurries, using different dewatering methods, such as gravitational thickening or filter pressing.
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Affiliation(s)
- Shanlin Xu
- College of Civil Engineering, Zhejiang University of Technology, Hangzhou, 310023, China.
| | - Junqiang Shi
- College of Civil Engineering, Zhejiang University of Technology, Hangzhou, 310023, China.
| | - Jing Deng
- College of Civil Engineering, Zhejiang University of Technology, Hangzhou, 310023, China.
| | - Honglei Sun
- College of Civil Engineering, Zhejiang University of Technology, Hangzhou, 310023, China.
| | - Jiawei Wu
- College of Civil Engineering, Zhejiang University of Technology, Hangzhou, 310023, China.
| | - Zhaohui Ye
- College of Civil Engineering, Zhejiang University of Technology, Hangzhou, 310023, China.
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Badawi AK, Salama RS, Mostafa MMM. Natural-based coagulants/flocculants as sustainable market-valued products for industrial wastewater treatment: a review of recent developments. RSC Adv 2023; 13:19335-19355. [PMID: 37377880 PMCID: PMC10291875 DOI: 10.1039/d3ra01999c] [Citation(s) in RCA: 22] [Impact Index Per Article: 22.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2023] [Accepted: 06/13/2023] [Indexed: 06/29/2023] Open
Abstract
Industrial wastewater is categorized as a voracious consumer of fresh water and a high-strength source of pollution. Coagulation-flocculation is a simple and cost-effective technique for removing organic/inorganic compounds and colloidal particles from industrial effluents. Despite the outstanding natural properties, biodegradability, and efficacy of natural coagulants/flocculants (NC/Fs) in industrial wastewater treatment, their significant potential to remediate such effluents is underappreciated, particularly in commercial scale applications. Most reviews on NC/Fs focused on the possible application of plant-based sources such as plant seeds, tannin, certain vegetables/fruit peels, and their lab-scale potential. Our review expands the scope by examining the feasibility of using natural materials from other sources for industrial effluent decontamination. By analyzing the latest data on NC/Fs, we identify the most promising preparation techniques for making these materials stable enough to compete with traditional options in the marketplace. An interesting presentation of the results of various recent studies has also been highlighted and discussed. Additionally, we highlight the recent success of using magnetic-natural coagulants/flocculants (M-NC/Fs) in treating diverse industrial effluents, and discuss the potential for reprocessing spent materials as a renewable resource. The review also offers different concepts for suggested large-scale treatment systems used by MN-CFs.
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Affiliation(s)
- Ahmad K Badawi
- Civil Engineering Department, El-Madina Higher Institute for Engineering and Technology Giza 12588 Egypt
| | - Reda S Salama
- Basic Science Department, Faculty of Engineering, Delta University for Science and Technology Gamasa Egypt
| | - Mohamed Mokhtar M Mostafa
- Chemistry Department, Faculty of Science, King Abdulaziz University P.O. Box 80203 Jeddah 21589 Saudi Arabia
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Nguyen TH, Nguyen LPD, Nguyen TTP, Le MXA, Kieu LTT, To HT, Bui TT. Optimization Conditions to Obtain Cationic Polyacrylamide Emulsion Copolymers with Desired Cationic Degree for Different Wastewater Treatments. Polymers (Basel) 2023; 15:2693. [PMID: 37376339 DOI: 10.3390/polym15122693] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2023] [Revised: 06/11/2023] [Accepted: 06/13/2023] [Indexed: 06/29/2023] Open
Abstract
The synthesis of cationic polyacrylamides (CPAMs) with the desired cationic degree and molecular weight is essential for various industries, including wastewater treatment, mining, paper, cosmetic chemistry, and others. Previous studies have already demonstrated methods to optimize synthesis conditions to obtain high-molecular-weight CPAM emulsions and the effects of cationic degrees on flocculation processes. However, the optimization of input parameters to obtain CPAMs with the desired cationic degrees has not been discussed. Traditional optimization methods are time-consuming and costly when it comes to on-site CPAM production because the input parameters of CPAM synthesis are optimized using single-factor experiments. In this study, we utilized the response surface methodology to optimize the synthesis conditions, specifically the monomer concentration, the content of the cationic monomer, and the content of the initiator, to obtain CPAMs with the desired cationic degrees. This approach overcomes the drawbacks of traditional optimization methods. We successfully synthesized three CPAM emulsions with a wide range of cationic degrees: low (21.85%), medium (40.25%), and high (71.17%) levels of cationic degree. The optimized conditions for these CPAMs were as follows: monomer concentration of 25%, content of monomer cation of 22.5%, 44.41%, and 77.61%, respectively, and initiator content of 0.475%, 0.48%, and 0.59%, respectively. The developed models can be utilized to quickly optimize conditions for synthesizing CPAM emulsions with different cationic degrees to meet the demands of wastewater treatment applications. The synthesized CPAM products performed effectively in wastewater treatment, with the treated wastewater meeting the technical regulation parameters. 1H-NMR, FTIR, SEM, BET, dynamic light scattering, and gel permeation chromatography were employed to confirm the structure and surface of the polymers.
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Affiliation(s)
- Tung Huy Nguyen
- Center for Polymer Composite and Paper, School of Chemical Engineering, Hanoi University of Science and Technology, Hanoi 11600, Vietnam
| | - Linh Pham Duy Nguyen
- Center for Polymer Composite and Paper, School of Chemical Engineering, Hanoi University of Science and Technology, Hanoi 11600, Vietnam
| | - Thao Thi Phuong Nguyen
- Center for Polymer Composite and Paper, School of Chemical Engineering, Hanoi University of Science and Technology, Hanoi 11600, Vietnam
| | - Minh Xuan Anh Le
- Department of Pharmaceutical Chemistry and Pesticides Tech, School of Chemical Engineering, Hanoi University of Science and Technology, Hanoi 11600, Vietnam
| | - Linh Thi Thuy Kieu
- Department of Chemical Process Equipment, School of Chemical Engineering, Hanoi University of Science and Technology, Hanoi 11600, Vietnam
| | - Huong Thi To
- Lab of Petrochemical Refining & Catalysis, School of Chemical Engineering, Hanoi University of Science and Technology, Hanoi 11600, Vietnam
| | - Thanh Tien Bui
- Center for Polymer Composite and Paper, School of Chemical Engineering, Hanoi University of Science and Technology, Hanoi 11600, Vietnam
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Deng R, Lai J, Liu Z, Song B, Liu H, Chen D, Zuo G, Yang Z, Meng F, Gong T, Song M. Insights into the role of ·OH generated in Fe 2+/CaO 2/coal slime system for efficient extracellular polymeric substances degradation to improve dewaterability of sewage sludge. CHEMOSPHERE 2023; 326:138443. [PMID: 36935059 DOI: 10.1016/j.chemosphere.2023.138443] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/28/2022] [Revised: 03/07/2023] [Accepted: 03/17/2023] [Indexed: 06/18/2023]
Abstract
The disposal of massive sewage sludge and coal slime is a problem facing municipalities in China. A hypothesis for the co-disposal of sludge and coal slime is proposed to improve dewaterability by utilizing the beneficial role of coal slime as a filter assist and CaO2 enhanced system in this research. Results showed that capillary suction time, specific resistance to filtration and water content decreased dramatically from 49.3 s, 13.2 × 1012 m/kg and 84.85% to 19.1 s, 1.0 × 1012 m/kg and 50.07%, respectively, under the optimal conditions with 0.3/0.1/0.3-Fe2+/CaO2/coal slime g/g DS. The hydroxyl radicals generated in the Fe2+/CaO2 process acted on extracellular polymeric substances (EPS), resulting in a drop in the ratio of α-helix/(β-sheet + random coil) in the secondary structure of EPS proteins and a reduction in the concentration of aromatic proteins and tryptophan-like substances in TB-EPS, thereby enhancing the sludge dewaterability. Furthermore, coal slime as the skeleton building material induced a rise in sludge particle size and contact angle, lowering the hydrophilicity, compressibility of sludge and providing more channels to facilitate water flow. This work verified the promising application prospect of the Fe2+/CaO2/coal slime combined system in the enhancement of sludge dewaterability.
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Affiliation(s)
- Rong Deng
- Key Laboratory of Energy Thermal Conversion and Control of Ministry of Education, School of Energy and Environment, Southeast University, Nanjing, Jiangsu 210096, China
| | - Jiahao Lai
- Key Laboratory of Energy Thermal Conversion and Control of Ministry of Education, School of Energy and Environment, Southeast University, Nanjing, Jiangsu 210096, China
| | - Zonghao Liu
- Key Laboratory of Energy Thermal Conversion and Control of Ministry of Education, School of Energy and Environment, Southeast University, Nanjing, Jiangsu 210096, China
| | - Bing Song
- Key Laboratory of Energy Thermal Conversion and Control of Ministry of Education, School of Energy and Environment, Southeast University, Nanjing, Jiangsu 210096, China
| | - Huan Liu
- School of Energy and Power Engineering, Huazhong University of Science and Technology, Wuhan, Hubei 430070, China
| | - Dandan Chen
- School of Energy & Mechanical Engineering, Nanjing Normal University, Nanjing, Jiangsu 210023, China
| | - Gancheng Zuo
- School of Environment, Nanjing Normal University, Nanjing, Jiangsu 210023, China
| | - Zhen Yang
- School of Chemistry and Materials Science, Nanjing Normal University, Nanjing, Jiangsu 210023, China
| | - Fanyue Meng
- Key Laboratory of Energy Thermal Conversion and Control of Ministry of Education, School of Energy and Environment, Southeast University, Nanjing, Jiangsu 210096, China
| | - Tingting Gong
- Key Laboratory of Energy Thermal Conversion and Control of Ministry of Education, School of Energy and Environment, Southeast University, Nanjing, Jiangsu 210096, China
| | - Min Song
- Key Laboratory of Energy Thermal Conversion and Control of Ministry of Education, School of Energy and Environment, Southeast University, Nanjing, Jiangsu 210096, China.
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Chang H, Zhao Y, Xu A, Damgaard A, Christensen TH. Mini-review of inventory data for the dewatering and drying of sewage sludge. WASTE MANAGEMENT & RESEARCH : THE JOURNAL OF THE INTERNATIONAL SOLID WASTES AND PUBLIC CLEANSING ASSOCIATION, ISWA 2023; 41:1081-1088. [PMID: 36633153 DOI: 10.1177/0734242x221139170] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/16/2023]
Abstract
Technological comparison and system modelling of sewage sludge treatment are important in terms of sustainable development and climate change mitigation. Dewatering and drying are important processes for reducing volume for transportation and often a requirement for further sludge treatment. Inventory data on mass transfers and material and energy consumptions are therefore crucial in improving and understanding sludge management systems. Reviewing the scientific literature (2003-2021) revealed 55 and 21 datasets on dewatering and drying of sewage sludge, respectively. The scarcity of data did not allow for identifying detailed relationships between inputs and outputs for the technologies, but the reviewed data can serve as the first port of call when planning sludge management. The average total solid (TS) content obtained was statistically different for mechanical dewatering (MDW), deep dewatering, bio-drying (BDR) and thermal drying (TDR). Loss of volatile solids (VS) during dewatering is barely described, but a substantial VS loss was observed for TDR (8%) and BDR (27%). The use of chemical agents in MDW showed typical values of 5-15 g kg-1 TS. The use of energy is low for MDW (average of 0.12 and 0.26 kWh kg-1 TS for raw and digested sludges, respectively) but substantially higher for TDR (average of 3.8 kWh kg-1 TS). The justified inventory data for sludge dewatering and drying provide essential support to system modelling and technological comparison in future studies, but additional data from full-scale plants on energy consumption and the composition of removed water are strongly requested to improve the inventory.
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Affiliation(s)
- Huimin Chang
- School of Environment, Beijing Normal University, Beijing, China
| | - Yan Zhao
- School of Environment, Beijing Normal University, Beijing, China
| | - Ankun Xu
- School of Environment, Beijing Normal University, Beijing, China
| | - Anders Damgaard
- Department of Environmental Engineering, Technical University of Denmark, Kongens Lyngby, Denmark
| | - Thomas H Christensen
- Department of Environmental Engineering, Technical University of Denmark, Kongens Lyngby, Denmark
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