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Jia W, Li Y, Chen C, Wu Y, Liang Y, Du J, Feng X, Wang H, Wu Q, Guo WQ. Unveiling the fate of metal leaching in bimetal-catalyzed Fenton-like systems: pivotal role of aqueous matrices and machine learning prediction. JOURNAL OF HAZARDOUS MATERIALS 2024; 477:135291. [PMID: 39047571 DOI: 10.1016/j.jhazmat.2024.135291] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/16/2024] [Revised: 07/05/2024] [Accepted: 07/20/2024] [Indexed: 07/27/2024]
Abstract
Metal-based catalytic materials exhibit exceptional properties in degrading emerging pollutants within Fenton-like systems. However, the potential risk of metal leaching has become pressing environmental concern. This study addressed scientific issues pertaining to the leaching behavior and control strategies for metal-based catalytic materials. Innovative cobalt-aluminum hydrotalcite (CoAl-LDH) triggered peroxymonosulfate (PMS) activation system was constructed and achieved near-complete removal of Ciprofloxacin (CIP) across diverse water quality environments. Notably, it was found that the tunable ion exchange and Al3+ stabilization of CoAl-LDH occurred due to the particularity of neutral water quality, resulting in significantly lower Co2+ leaching levels (0.321 mg/L) compared to acidic conditions (5.103 mg/L). In light of this, machine learning technology was then employed for the first time to simulate the dynamic trend of Co2+ leaching and elucidated the critical regulatory roles and mechanisms of Al3+, aqueous matrix, and reaction rate. Furthermore, degradation systems based on different water quality and metal leaching levels regulated the generation levels of SO4.- and O2∙-, and the unique advantages of free radical attack paths were clarified through CIP degradation products and ecotoxicity analysis. These findings introduced novel insights and approaches for engineering application and pollution control in metal-based Fenton-like water treatment.
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Affiliation(s)
- Wenrui Jia
- State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090, China
| | - Ying Li
- State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090, China
| | - Chuchu Chen
- State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090, China
| | - Yaohua Wu
- State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090, China
| | - Yongqi Liang
- State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090, China
| | - Juanshan Du
- Department of Energy Engineering, Korea Institute of Energy Technology (KENTECH), Naju 58330, South Korea
| | - Xiaochi Feng
- State Key Laboratory of Urban Water Resource and Environment, School of Civil and Environmental Engineering, Harbin Institute of Technology (Shenzhen), Shenzhen 518055, China
| | - Huazhe Wang
- State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090, China.
| | - Qinglian Wu
- State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090, China
| | - Wan-Qian Guo
- State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090, China
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2
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Xu J, Zhan Y, Imtiyaz Cheema A, Cao R, Yang C, Wang H, Jin Z, Xie Z, Dong B. Low-cost optimization of industrial textile landfill sludge re-dewatering using ferrous sulfate and blast furnace slag. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2024; 366:121748. [PMID: 38991352 DOI: 10.1016/j.jenvman.2024.121748] [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: 06/29/2024] [Accepted: 07/03/2024] [Indexed: 07/13/2024]
Abstract
This study was based on an industrial sludge landfill with a scale of 1 million cubic meters, which had been filled for more than 10 years. It focused on the secondary dewatering of industrial textile landfill sludge (LS) with a total organic carbon (TOC) content greater than 50% and a volatile suspended solids to suspended solids (VSS/SS) ratio of 0.59. A response surface methodology (RSM) model was established using the coagulant ferrous sulfate (FeSO4) and conditioning agents such as hydrated magnesium oxide (MgO), blast furnace slag (BFS), and calcium oxide (CaO). By solving the RSM equations for the respective indicators, the optimal dosages of FeSO4, MgO, and BFS were determined to be 90 mg/g of dry sludge (DS), and for CaO 174.85 mg/g DS. Further examinations of the dewatering performance, apparent properties, extracellular polymeric substances (EPS) components, rheological characteristics, moisture distribution, and pollutant content variation led to the development of a green waste-based dewatering agent composed of FeSO4 and BFS. In small-scale diaphragm plate and frame filter press tests, the optimal water content (WC) was 69.11%. In the final production-scale experiments, it was 65.72%, with the actual application cost being only 13.07 $/ton DS. Additionally, when FeSO4 and BFS were used together, the combined action of Fe and Si could significantly reduce the biotoxicity of heavy metals (HMs), cut down 75.2% of the LS's TOC, and effectively reduced the leaching of organic substances from the leachate, which was beneficial for subsequent disposal. In conclusion, the combined use of FeSO4 and BFS for the secondary dewatering of industrial textile LS was economically efficient, effective in dewatering, and had significant harm reduction effects, making it a worthwhile for waste treatment.
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Affiliation(s)
- Jingjing Xu
- School of Environment and Architecture, University of Shanghai for Science and Technology, Shanghai, 200093, PR China
| | - Yong Zhan
- School of Environment and Architecture, University of Shanghai for Science and Technology, Shanghai, 200093, PR China
| | - Ayesha Imtiyaz Cheema
- College of Environmental Science and Engineering, Tongji University, Shanghai, 200092, PR China
| | - Runqin Cao
- School of Environment and Architecture, University of Shanghai for Science and Technology, Shanghai, 200093, PR China
| | - Chaoqi Yang
- School of Environment and Architecture, University of Shanghai for Science and Technology, Shanghai, 200093, PR China
| | - Hui Wang
- College of Environmental Science and Engineering, Tongji University, Shanghai, 200092, PR China
| | - Zhihao Jin
- School of Environment and Architecture, University of Shanghai for Science and Technology, Shanghai, 200093, PR China
| | - Zelin Xie
- School of Environment and Architecture, University of Shanghai for Science and Technology, Shanghai, 200093, PR China
| | - Bin Dong
- College of Environmental Science and Engineering, Tongji University, Shanghai, 200092, PR China.
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Liu Z, Luo F, He L, Wang S, Wu Y, Chen Z. Physical conditioning methods for sludge deep dewatering: A critical review. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2024; 360:121207. [PMID: 38788408 DOI: 10.1016/j.jenvman.2024.121207] [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: 01/22/2024] [Revised: 04/17/2024] [Accepted: 05/18/2024] [Indexed: 05/26/2024]
Abstract
Sludge is an inevitable waste product of sewage treatment with a high water content and large volume, it poses a significant threat of secondary pollution to both water and the atmosphere without proper disposal. In this regard, dewatering has emerged as an attractive method in sludge treatment, as it can reduce the sludge volume, enhance its transportability and calorific value, and even decrease the production of landfill leachate. In recent years, physical conditioning methods including non-chemical conditioners or energy input alone, have been extensively researched for their potential to enhance sludge dewatering efficiency, such as thermal treatment, freeze-thaw, microwave, ultrasonic, skeleton builders addition, and electro-dewatering, as well as combined methods. The main objective of this paper is to comprehensively evaluate the dewatering capacity of various physical conditioning methods, and identify key factors affecting sludge dewatering efficiency. In addition, future research anticipated directions and outlooks are proposed. This work is expected to provide valuable insights for developing efficient, eco-friendly, and low-energy consumption techniques for deep sludge dewatering.
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Affiliation(s)
- Zhuo Liu
- Key Laboratory of Material Chemistry for Energy Conversion and Storage, Ministry of Education, Hubei Key Laboratory of Material Chemistry and Service Failure, School of Chemistry and Chemical Engineering, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Fang Luo
- Key Laboratory of Material Chemistry for Energy Conversion and Storage, Ministry of Education, Hubei Key Laboratory of Material Chemistry and Service Failure, School of Chemistry and Chemical Engineering, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Lingzhi He
- Key Laboratory of Material Chemistry for Energy Conversion and Storage, Ministry of Education, Hubei Key Laboratory of Material Chemistry and Service Failure, School of Chemistry and Chemical Engineering, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Siqi Wang
- Key Laboratory of Material Chemistry for Energy Conversion and Storage, Ministry of Education, Hubei Key Laboratory of Material Chemistry and Service Failure, School of Chemistry and Chemical Engineering, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Yi Wu
- Key Laboratory of Material Chemistry for Energy Conversion and Storage, Ministry of Education, Hubei Key Laboratory of Material Chemistry and Service Failure, School of Chemistry and Chemical Engineering, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Zhuqi Chen
- Key Laboratory of Material Chemistry for Energy Conversion and Storage, Ministry of Education, Hubei Key Laboratory of Material Chemistry and Service Failure, School of Chemistry and Chemical Engineering, Huazhong University of Science and Technology, Wuhan 430074, China.
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4
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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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5
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Zhang Y, Pei J, Zheng S, Li Y, Lv N, Ma L. Enhanced dewaterability of sludge by Fe(II)-sludge biochar activate persulfate. ENVIRONMENTAL TECHNOLOGY 2024; 45:854-866. [PMID: 36161866 DOI: 10.1080/09593330.2022.2129457] [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: 05/14/2022] [Accepted: 09/17/2022] [Indexed: 06/16/2023]
Abstract
Sludge biochar supported Fe(II) (Fe(II)-SBC) was successfully prepared using waste activated sludge as peroxydisulfate (PDS) activator to condition sludge for deep dewatering. The experimental results showed that Fe(II)-SBC with FeO on it could effectively active PDS to produce SO 4 - ⋅ and HO ⋅ . The radicals could destroy the structure of sludge cells and extracellular polymeric substance (EPS), transformed the hydrophilic and tightly bound EPS into soluble-EPS, degrade partial proteins and polysaccharides and released bound water. The negatively charged groups on sludge floc were dripped off by SO 4 - ⋅ /HO ⋅ or neutralized with Fe2+, Fe3+, H+, or Fe(II)-SBC, leading to an increase in zeta potential to -2.24 mV and sludge destabilization. The residual Fe(II)-SBC served as a skeleton builder that decreased the compression coefficient of the sludge cake to 0.75. Under the combined functions, the CST and SRF were reduced by 70% and 82.7%, respectively, and Wc was reduced to 72.4%. The byproducts of Fe3+ and SO42- finally remained in sludge cake in the form of NaFeSi2O6 and CaSO4.
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Affiliation(s)
- Yanping Zhang
- School of Civil Engineering and Transportation, Hebei University of Technology, Tianjin, People's Republic of China
| | - Jiahua Pei
- School of Civil Engineering and Transportation, Hebei University of Technology, Tianjin, People's Republic of China
| | - Songchao Zheng
- School of Civil Engineering and Transportation, Hebei University of Technology, Tianjin, People's Republic of China
| | - Yibing Li
- School of Civil Engineering and Transportation, Hebei University of Technology, Tianjin, People's Republic of China
| | - Ning Lv
- School of Civil Engineering and Transportation, Hebei University of Technology, Tianjin, People's Republic of China
| | - Liran Ma
- School of Civil Engineering and Transportation, Hebei University of Technology, Tianjin, People's Republic of China
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Ali OI, Azzam AB. Functional Ag-EDTA-modified MnO 2 nanocoral reef for rapid removal of hazardous copper from wastewater. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2023; 30:123751-123769. [PMID: 37991610 PMCID: PMC10746771 DOI: 10.1007/s11356-023-30805-0] [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: 09/08/2023] [Accepted: 10/27/2023] [Indexed: 11/23/2023]
Abstract
A novel MnO2@EDTA-Ag nanocoral reef was constructed via a simplified redox reaction followed by EDTA and Ag nanoparticles impregnation to capture hazardous copper (II) from wastewater. A comprehensive characterization of the synthesized materials was conducted. The morphology of MnO2@EDTA-Ag in the form of a nanocoral reef was constructed of two-dimensional nanoplatelets and nanorod-like nanostructures. The optimal adsorption conditions proposed by the Plackett-Burman design (PBD) that would provide a removal % of 99.95 were pH 5.5, a contact time of 32.0 min, a Cu(II) concentration of 11.2 mg L-1, an adsorbent dose of 0.05 g, and a temperature of 40.3 °C. The loading of Ag nanoparticles onto MnO2@EDTA improved the adsorption capability of MnO2@EDTA-Ag. Additionally, the recyclability of MnO2@EDTA-Ag nanocoral reef was maintained at 80% after three adsorption-desorption cycles, and there was no significant change in the XRD analysis before and after the recycling process, implying its stability. It was found that nanocoral reef-assisted EDTA formed a chelation/complexation reaction between COO- groups and C-N bonds of EDTA with Cu(II) ions. In addition, X-ray photoelectron spectroscopy (XPS) and Fourier transform infrared spectroscopy (FTIR) analysis proved the synergistic effect of the electrostatic interaction and chelation/complexation was responsible for the removal mechanism of Cu(II). Also, the results demonstrated no significant variation in MnO2@EDTA-Ag removal efficiency for all the tested real water samples, revealing its efficacy in wastewater treatment. Therefore, the current study suggests that MnO2@EDTA-Ag has substantial potential to be used as a feasible adsorbent for probable hazardous metals remediation.
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Affiliation(s)
- Omnia I Ali
- Chemistry Department, Faculty of Science, Helwan University, Cairo, 11795, Egypt.
| | - Ahmed B Azzam
- Chemistry Department, Faculty of Science, Helwan University, Cairo, 11795, Egypt
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Bi W, Chen M, Hu C, Sun H, Xu S, Jiang J, Wang L, Li X, Deng J. Insight into sludge dewatering by periodate driven directly with Fe(Ⅱ): Extracellular polymeric substances solubilization and mineralization. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2023; 344:118450. [PMID: 37413734 DOI: 10.1016/j.jenvman.2023.118450] [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: 03/10/2023] [Revised: 05/25/2023] [Accepted: 06/16/2023] [Indexed: 07/08/2023]
Abstract
The production of waste activated sludge is expanding in tandem with the significant growth in the global population. It is important to explore sludge pretreatment technology to achieve sludge reduction. In this study, deep sludge dewatering was achieved by using Fe2+-catalyzed periodate (Fe2+/PI) conditioning. The result showed that capillary suction time was reduced by 48.27% under the optimum Fe2+ and PI dosages. ·OH, FeⅣ, O2·-, 1O2, and IO3· generated from the reaction between Fe2+ and PI, while ·OH (49.79%) and FeⅣ (47.76%) contributed significantly to sludge dewatering. Investigations of the mechanism revealed that the synergistic action of radical species oxidation and iron species flocculation in Fe2+/PI conditioning led to the mineralization and aggregation of hydrophilic substances in extracellular polymeric substances. The hydrophobic groups on the protein surface were more exposed to soluble extracellular polymeric substances and reduced protein-water interaction. The variations in zeta potential and particle size also verified the presence of a synergistic effect of oxidation and flocculation. The morphology observations revealed that the increased frictional forces generated when water flowed over the raw sludge (RS) surface prevented the rapid passage of internal water. In addition, the hydrophobic and electrostatic interactions in the sludge samples were essential influences that promoted flocculation and sedimentation of the sludge. This research aids engineers by providing a new option to better optimize sludge management while also deepening understanding of the Fe2+/PI conditioning involved in sludge dewatering.
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Affiliation(s)
- Weiwei Bi
- College of Civil Engineering, Zhejiang University of Technology, Hangzhou, 310023, China; Zhejiang Key Laboratory of Civil Engineering Structures & Disaster Prevention and Mitigation Technology, Hangzhou, 310023, China
| | - Minjie Chen
- College of Civil Engineering, Zhejiang University of Technology, Hangzhou, 310023, China
| | - Chenkai Hu
- College of Civil Engineering, Zhejiang University of Technology, Hangzhou, 310023, China
| | - Honglei Sun
- College of Civil Engineering, Zhejiang University of Technology, Hangzhou, 310023, China; Zhejiang Key Laboratory of Civil Engineering Structures & Disaster Prevention and Mitigation Technology, Hangzhou, 310023, China
| | - Shanlin Xu
- College of Civil Engineering, Zhejiang University of Technology, Hangzhou, 310023, China; Zhejiang Key Laboratory of Civil Engineering Structures & Disaster Prevention and Mitigation Technology, Hangzhou, 310023, China
| | - Jiahong Jiang
- College of Civil Engineering, Zhejiang University of Technology, Hangzhou, 310023, China
| | - Lei Wang
- College of Civil Engineering, Zhejiang University of Technology, Hangzhou, 310023, China
| | - Xueyan Li
- School of Environmental Science and Engineering, Suzhou University of Science and Technology, Suzhou, 215009, China
| | - Jing Deng
- College of Civil Engineering, Zhejiang University of Technology, Hangzhou, 310023, China; Zhejiang Key Laboratory of Civil Engineering Structures & Disaster Prevention and Mitigation Technology, Hangzhou, 310023, China.
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Xiao B, Chen X, Zhang K, Zheng T, Bian C, Liu J, Li L, Liu J. Improving sewage sludge dewaterability via heterogeneous activation of persulfate by Fe-Al layered double hydroxide: Role of generated SO 4-•. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2023; 342:118194. [PMID: 37210818 DOI: 10.1016/j.jenvman.2023.118194] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/21/2023] [Revised: 05/07/2023] [Accepted: 05/15/2023] [Indexed: 05/23/2023]
Abstract
In this study, Fe-Al layered double hydroxide (Fe-Al LDH) was prepared and applied to activate persulfate to condition sewage sludge and improve its dewaterability. The results showed that Fe-Al LDH activated persulfate to generate a large amount of free radicals, which attacked extracellular polymeric substances and reduced their content, disrupted microbial cells, released bound water, decreased sludge particle size, increased sludge zeta potential, and improved sludge dewaterability. After sewage sludge was conditioned with Fe-Al LDH (0.20 g/g total solids (TS)) and persulfate (0.10 g/g TS) for 30 min, the capillary suction time of the sludge dropped from 52.0 s to 16.3 s, while the moisture content of the sludge cake decreased from 93.2% to 68.5%. The dominant active free radical produced by the Fe-Al LDH-activated persulfate was SO4-•. The maximum Fe3+ leaching of the conditioned sludge was only 102.67 ± 4.45 mg/L, thus effectively alleviating the secondary pollution of Fe3+. The leaching rate of 2.37% was significantly lower than that of the sludge homogeneously activated with Fe2+ (738.4 ± 26.07 mg/L and 71.00%).
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Affiliation(s)
- Benyi Xiao
- Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; University of Chinese Academy of Science, Beijing 100049, China
| | - Xiangyu Chen
- Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; University of Chinese Academy of Science, Beijing 100049, China
| | - Ke Zhang
- Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; University of Chinese Academy of Science, Beijing 100049, China
| | - Tianlong Zheng
- Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; University of Chinese Academy of Science, Beijing 100049, China.
| | - Chunlin Bian
- Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; Inner Mongolia University of Technology, Hohhot, Inner Mongolia, 010051, China
| | - Jianguo Liu
- Inner Mongolia University of Technology, Hohhot, Inner Mongolia, 010051, China.
| | - Lin Li
- Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; University of Chinese Academy of Science, Beijing 100049, China
| | - Junxin Liu
- Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; University of Chinese Academy of Science, Beijing 100049, China
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9
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Chen C, Zhang T, Lv L, Chen Y, Tang W, Tang S. A novel insight on the intensification mechanism of sludge dewaterability by ionic liquids. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2023; 331:117291. [PMID: 36657200 DOI: 10.1016/j.jenvman.2023.117291] [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: 10/04/2022] [Revised: 01/01/2023] [Accepted: 01/10/2023] [Indexed: 06/17/2023]
Abstract
The huge output of sewage sludge has caused a remarkable environmental burden. Sludge dewatering is considered as an important way to reduce the sludge volume. Five imidazole-based ionic liquids were used to improve the dewaterability of sewage sludge. 1-ethyl-3-methylimidazolium dihydrogen phosphate ([Emim][H2PO4]) was screened out as a potential conditioner of sludge due to its excellent dewatering performance and reusability. The solid content of sludge filter cake after treatment with [Emim][H2PO4] was about 10% higher than that of sludge treated by cationic polyacrylamides (CPAM). The intensification mechanism of ionic liquids to the improvement of sludge dewatering performance was studied. The presence of acidic ionic liquids [Emim][H2PO4] resulted the increase of zeta potential from -14.57 ± 0.81 mV to -5.60 ± 0.30 mV and led to the protonation of biopolymers. Acidic ionic liquids [Emim][H2PO4] inactivated the microorganism and led to a porous and unconsolidated structure of the solid sludge particles. All these effects were conducive to destroy the microstructure of sludge and release water. However, [Emim]Cl, [Bmim][OTf] and [Hmim][OTf] showed little effect on the protonation of ionizable functional groups at near-neutral environment. The dissolution of biopolymer decreased the zeta potential and strengthened the electrostatic repulsion. So, they showed weaker intensification effects than CPAM.
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Affiliation(s)
- Changtao Chen
- Sichuan Base of International Science and Technology Cooperation for Green Chemical Industry, School of Chemical Engineering, Sichuan University, Chengdu, 610065, China.
| | - Tao Zhang
- Sichuan Base of International Science and Technology Cooperation for Green Chemical Industry, School of Chemical Engineering, Sichuan University, Chengdu, 610065, China.
| | - Li Lv
- Sichuan Base of International Science and Technology Cooperation for Green Chemical Industry, School of Chemical Engineering, Sichuan University, Chengdu, 610065, China.
| | - Yanxiao Chen
- Sichuan Base of International Science and Technology Cooperation for Green Chemical Industry, School of Chemical Engineering, Sichuan University, Chengdu, 610065, China.
| | - Wenxiang Tang
- Sichuan Base of International Science and Technology Cooperation for Green Chemical Industry, School of Chemical Engineering, Sichuan University, Chengdu, 610065, China.
| | - Shengwei Tang
- Sichuan Base of International Science and Technology Cooperation for Green Chemical Industry, School of Chemical Engineering, Sichuan University, Chengdu, 610065, China.
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Chen X, Mu S, Luo Y. Degradation of petroleum pollutants in oil-based drilling cuttings using an Fe 2+-based Fenton-like advanced oxidation processes. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2023; 30:37669-37678. [PMID: 36574125 DOI: 10.1007/s11356-022-24925-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/23/2022] [Accepted: 12/19/2022] [Indexed: 06/18/2023]
Abstract
Oil-based drilling cuttings (OBDC) contain a large amount of total petroleum hydrocarbon (TPH) pollutants, which are hazardous to the environment. In this study, Fe2+-activating hydrogen peroxide (Fe2+/H2O2), peroxymonosulfate (Fe2+/PMS), and peroxydisulfate (Fe2+/PDS) advanced oxidation processes (AOPs) were used to treat OBDC due to the difference in the degradation capacity of TPH caused by the type of free radical generated and effective activation conditions observed for the different oxidants studied. The results showed that the oxidant concentration, Fe2+ dosage, and reaction time in the three AOPs were greatly positively correlated with the TPH removal rate in a certain range. The initial pH value had a significant effect on the Fe2+/H2O2 process, and its TPH removal rate was negatively correlated in the pH range from 3 to 11. However, the Fe2+/PMS and Fe2+/PDS processes only displayed lower TPH removal rates under neutral conditions and tolerated a wider range of pH conditions. The optimal TPH removal rates observed for the Fe2+/H2O2, Fe2+/PMS, and Fe2+/PDS processes were 45.04%, 42.75%, and 44.95%, respectively. Fourier transform infrared spectrometer and gas chromatography-mass spectrometer analysis showed that the alkanes in OBDC could be effectively removed using the three processes studied, and their degradation ability toward straight-chain alkanes was in the order of Fe2+/PMS > Fe2+/PDS > Fe2+/H2O2, among which Fe2+/PMS exhibited the optimal removal effect for aromatic hydrocarbons. Scanning electron microscope, energy dispersive spectroscopy, and X-ray diffraction results showed no significant changes in the elemental and mineral composition of OBDC before and after treatment. Therefore, this study provided a theoretical reference for the effective degradation of TPH pollutants in OBDC.
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Affiliation(s)
- Xinglong Chen
- Faculty of Geosciences and Environmental Engineering, Southwest Jiaotong University, Chengdu, 611756, China
| | - Shiqi Mu
- Faculty of Geosciences and Environmental Engineering, Southwest Jiaotong University, Chengdu, 611756, China
| | - Yuanfeng Luo
- Department of Ecology and Environment of Sichuan Province, Sichuan Academy of Environmental Policy and Planning, Chengdu, 610093, China.
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11
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Xiao H, Liu Q, Wang Y, Zhu Y, Fang D, Wu G, Zeng Z, Peng H. Improved Dewaterability of Waste Activated Sludge by Fe(II)-Activated Potassium Periodate Oxidation. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2022; 19:14726. [PMID: 36429442 PMCID: PMC9690991 DOI: 10.3390/ijerph192214726] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/18/2022] [Revised: 11/03/2022] [Accepted: 11/08/2022] [Indexed: 06/16/2023]
Abstract
Fe(II)-activated potassium periodate (KIO4) oxidation was used to improve the dewaterability of waste-activated sludge for the first time. Compared with those of raw sludge, the capillary suction time (CST), specific resistance filtration (SRF), and water content of filter cake (WC) of sludge treated using the Fe(II)/KIO4 process under the optimal conditions (i.e., the initial pH = 6.8, KIO4 dose = 1.4 mmol/g volatile suspended solids, Fe(II)/KIO4 molar ratio = 1.2) decreased by 64.34%, 84.13%, and 6.69%, respectively. For conditioned sludge flocs, the Zeta potential and particle size were increased, and hydrophilic proteins in extracellular polymeric substances (EPS) were partly degraded, accompanied by the transformation of tightly bound EPS into soluble EPS and the conversion of dense sludge flocs into loose and porous ones. During Fe(II)/KIO4 oxidation, Fe(IV) and the accompanying •OH were determined as the predominant reactive species and the underlying mechanism of sludge EPS degradation was proposed. This work provides a prospective method for conditioning the sludge dewaterability.
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12
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Jiang F, Feng X, Jiang X, Wang P. Enhanced dewaterability of lake dredged sediments by electrochemical oxidation of peroxydisulfate on BDD anode. CHEMOSPHERE 2022; 307:135832. [PMID: 35963373 DOI: 10.1016/j.chemosphere.2022.135832] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/16/2022] [Revised: 07/21/2022] [Accepted: 07/22/2022] [Indexed: 06/15/2023]
Abstract
Dredged sediments, as a product of mitigating endogenous pollution of rivers and lakes, cause severe environmental pollution without suitable disposal. To reduce dredged sediments, the electrochemical oxidation (EO) of peroxydisulfate (PS) on a boron-doped diamond (BDD) anode (EO/BDD-PS) was utilized to enhance the dewaterability of the dredged sediments. The soluble chemical oxygen demand increased in the EO/BDD-PS system, and more than 70.0% of the specific resistance to filtration was reduced by EO/BDD-PS within 20 min. The optimal conditions were determined to be as follows: current density, 30 mA cm-2; PS dosage 4 g L-1; and initial pH, 6.96. After treatment with EO/BDD-PS, the electronegativity of the sludge flocs was alleviated and the particle size increased from 7.61 to 10.64 μm. Furthermore, proteins and polysaccharides were degraded, and tightly bound extracellular polymeric substances (TB-EPS) and loosely bound EPS (LB-EPS) were effectively transported to soluble EPS (S-EPS). Furthermore, humification of organic matter occurred in S-EPS and LB-EPS when the dredged sediment was treated with EO/BDD-PS. Dominant hydroxyl radicals (•OH) and sulfate radicals (SO4•-) were generated in the EO/BDD-PS system. Moreover, the efficiency of the filtrate as an electrolyte decreased slightly after recycling five times. Therefore, this method may be economical for enhancing the dewaterability of dredged sediments.
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Affiliation(s)
- Feng Jiang
- National Engineering Laboratory for Lake Pollution Control and Ecological Restoration, State Environmental Protection Key Laboratory for Lake Pollution Control, Chinese Research Academy of Environmental Sciences, Anwai, Beiyuan, Beijing 100012, China
| | - Xianlu Feng
- Beijing Key Lab for Source Control Technology of Water Pollution, Engineering Research Center for Water Pollution Source Control and Eco-remediation, College of Environmental Science and Engineering, Beijing Forestry University, Beijing, 100083, China
| | - Xia Jiang
- National Engineering Laboratory for Lake Pollution Control and Ecological Restoration, State Environmental Protection Key Laboratory for Lake Pollution Control, Chinese Research Academy of Environmental Sciences, Anwai, Beiyuan, Beijing 100012, China.
| | - Pengfei Wang
- National Engineering Laboratory for Lake Pollution Control and Ecological Restoration, State Environmental Protection Key Laboratory for Lake Pollution Control, Chinese Research Academy of Environmental Sciences, Anwai, Beiyuan, Beijing 100012, China.
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13
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Yu H, Zhang D, Gu L, Wen H, Zhu N. Coupling sludge-based biochar and electrolysis for conditioning and dewatering of sewage sludge: Effect of char properties. ENVIRONMENTAL RESEARCH 2022; 214:113974. [PMID: 35952734 DOI: 10.1016/j.envres.2022.113974] [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: 06/03/2022] [Revised: 07/07/2022] [Accepted: 07/20/2022] [Indexed: 06/15/2023]
Abstract
The addition of sludge-based biochar during electrochemical pretreatment of sewage sludge, as an efficient hybrid technology, is potentially to be applied in sludge deep-dewatering. The chars functioned as conductors, catalysts and skeleton particles could enhance the sludge dewaterability and increase the calorific value of the dewatered sludge cake. However, the effect of synthesis conditions on the char properties and further on the dewatering performance is still unknown. Herein, the sludge-based particle electrodes (SPEs) under three main synthesis conditions, including liquid-solid ratio, pyrolysis temperature and time, were prepared. The sludge-based biochars (i.e., SPE-400, SPE-600, and SPE-800 pyrolyzed under 400, 600 and 800 °C, respectively) were characterized and utilized as three-dimensional electrodes during sludge electrolysis. The increased pyrolysis temperature (within 400-800 °C) resulted in the enrichment of metallic ions and increment of specific surface area and pore volume of SPE, which led to the increased catalysis and adsorption sites for viscous proteins (PNs). Particularly, the pores of SPE-800 provided more drainage channels as skeleton builders. Compared with raw sludge, the capillary suction time (CST) and the specific resistance of filtration (SRF) of the treated sludge with 3D-SPE-800 were reduced by 58.12% and 81.01%, respectively, but the net sludge solids yield (YN) was increased by 87.05%. The highest decrease of hydrophilic α-Helix content in PNs (from 9.93% to 7.30%) was observed when using SPE-800 as particle electrode, revealing the crucial role of char characteristics on protein reduction and subsequent dewatering enhancement. The synergistic effects of electrolysis and sludge-based biochar provided a new insight for a closed-loop pretreatment of sewage sludge in the wastewater treatment plant.
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Affiliation(s)
- Haixiang Yu
- School of Environment and Architecture, University of Shanghai for Science and Technology, Shanghai, 200093, PR China
| | - Daofang Zhang
- School of Environment and Architecture, University of Shanghai for Science and Technology, Shanghai, 200093, PR China
| | - Lin Gu
- School of Environment and Architecture, University of Shanghai for Science and Technology, Shanghai, 200093, PR China; School of Environment Engineering, Shanghai Jiao Tong University, Shanghai, 200240, PR China.
| | - Haifeng Wen
- School of Environment and Architecture, University of Shanghai for Science and Technology, Shanghai, 200093, PR China
| | - Nanwen Zhu
- School of Environment Engineering, Shanghai Jiao Tong University, Shanghai, 200240, PR China
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14
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Rui Y, Qian C. Characteristics of Different Bacteria and Their Induced Biominerals. J IND ENG CHEM 2022. [DOI: 10.1016/j.jiec.2022.08.032] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022]
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15
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Zhang Q, Fang S, Cheng X, Wang F, Zhang L, Huang W, Du W, Fang F, Cao J, Luo J. Persulfate-based strategy for promoted acesulfame removal during sludge anaerobic fermentation: Combined chemical and biological effects. JOURNAL OF HAZARDOUS MATERIALS 2022; 434:128922. [PMID: 35452991 DOI: 10.1016/j.jhazmat.2022.128922] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/25/2022] [Revised: 03/28/2022] [Accepted: 04/11/2022] [Indexed: 06/14/2023]
Abstract
The acesulfame (ACE) degradation in waste activated sludge (WAS) via direct anaerobic fermentation is difficult and the efficient elimination techniques are imperative for the ultimate safe WAS disposal. Persulfate (PS)-based approach was developed to promote the ACE removal during WAS anaerobic fermentation. Results demonstrated the effectiveness of PS-based treatments on ACE degradation, and the ACE removal efficiency was respectively 48.2% and 96.2% in the PS and PS/Fe-treated reactors while it was only 6.0% in the control reactor. Mechanism explorations revealed that the active free radicals (i.e. OH• and SO4•-) generated in the PS-based reactors were the key oxidative species for the ACE degradation. However, such effects were interfered by the released soluble substrates (i.e. protein, carbohydrate and inorganic ions) during anaerobic fermentation by competing and/or quenching free radicals, which caused the deceleration of the ACE removal efficiency. Moreover, the PS-based treatment facilitated the enrichment of functional microorganisms (i.e. Phyllobacteriaceae and Bradyrhizobiaceae) and upregulated the critical genes (i.e. pncB and nadE) involved in the ACE degradation. Based on the density functional theory (DFT) and metabolic intermediates analysis, the hydroxylation and oxidative ring-opening were the two main proposed metabolic pathways for ACE degradation. Overall, the combined chemical and biological metabolism effects collectively contributed to the efficient ACE degradation, and it provided a novel and effective strategy for refractory pollutants removal during WAS anaerobic fermentation.
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Affiliation(s)
- Qin Zhang
- Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Ministry of Education, Hohai University, Nanjing 210098, China; College of Environment, Hohai University, Nanjing 210098, China
| | - Shiyu Fang
- Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Ministry of Education, Hohai University, Nanjing 210098, China; College of Environment, Hohai University, Nanjing 210098, China
| | - Xiaoshi Cheng
- Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Ministry of Education, Hohai University, Nanjing 210098, China; College of Environment, Hohai University, Nanjing 210098, China
| | - Feng Wang
- Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Ministry of Education, Hohai University, Nanjing 210098, China; College of Environment, Hohai University, Nanjing 210098, China
| | - Le Zhang
- Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Ministry of Education, Hohai University, Nanjing 210098, China; College of Environment, Hohai University, Nanjing 210098, China
| | - Wenxuan Huang
- Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Ministry of Education, Hohai University, Nanjing 210098, China; College of Environment, Hohai University, Nanjing 210098, China
| | - Wei Du
- Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Ministry of Education, Hohai University, Nanjing 210098, China; College of Environment, Hohai University, Nanjing 210098, China
| | - Fang Fang
- Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Ministry of Education, Hohai University, Nanjing 210098, China; College of Environment, Hohai University, Nanjing 210098, China
| | - Jiashun Cao
- Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Ministry of Education, Hohai University, Nanjing 210098, China; College of Environment, Hohai University, Nanjing 210098, China
| | - Jingyang Luo
- Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Ministry of Education, Hohai University, Nanjing 210098, China; College of Environment, Hohai University, Nanjing 210098, China; Anhui Provincial Key Laboratory of Environmental Pollution Control and Resource Reuse, China.
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16
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Chen C, Li H, Cui F, Wang Z, Liu X, Jiang G, Cheng T, Bai R, Song L. Novel combination of bioleaching and persulfate for the removal of heavy metals from metallurgical industry sludge. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2022; 29:33751-33763. [PMID: 35028841 DOI: 10.1007/s11356-021-18068-z] [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: 06/15/2021] [Accepted: 12/08/2021] [Indexed: 06/14/2023]
Abstract
The objective of this study was to remove heavy metals from metallurgical industry sludge by bioleaching alone and bioleaching combined with persulfate (PDS). The results showed that the removal of Cu, Zn, Pb, and Mn reached 70%, 83.8%, 25.2%, and 76.9% by bioleaching alone after 18 days, respectively. The experiment of bioleaching combined with PDS was carried out in which the optimal additive dosage of K2S2O8, 8 g/L, was added to bioleaching after 6 d. After 1 h, the removal of four heavy metals reached 75.1, 84.3, 36.7, and 81.6%, respectively. Compared with bioleaching alone, although the increase in removal efficiency was only slightly increased, the treatment cycle was distinctly shortened from 18 to 6 days + 1 h. The scanning electron microscopy (SEM) results showed that the surface morphology of the sludge was changed significantly by the combined treatment. The content of heavy metals was significantly reduced after bioleaching combined with PDS by energy dispersive X-ray spectroscopy (EDX). Through electron paramagnetic resonance (EPR) and free radical quenching experiments, it was indicated that sulfate radicals [Formula: see text] plays a leading role in the combined treatment. The treated sludge mainly existed in a stable form, and the bioavailability was reduced with European Community Bureau of Reference (BCR) morphology analysis. This study proved that the combination of bioleaching and PDS could not only shorten the treatment cycle but also further improve the efficiency of heavy metal leaching. It provides a novel treatment method for the removal of heavy metals from metallurgical industry sludge.
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Affiliation(s)
- Chen Chen
- School of Civil Engineering, Inner Mongolia University of Technology, Hohhot, 010051, People's Republic of China
| | - Huidong Li
- School of Civil Engineering, Inner Mongolia University of Technology, Hohhot, 010051, People's Republic of China.
| | - Fengjiao Cui
- School of Civil Engineering, Inner Mongolia University of Technology, Hohhot, 010051, People's Republic of China
| | - Zhixia Wang
- School of Civil Engineering, Inner Mongolia University of Technology, Hohhot, 010051, People's Republic of China
| | - Xinxin Liu
- School of Civil Engineering, Inner Mongolia University of Technology, Hohhot, 010051, People's Republic of China
| | - Gang Jiang
- School of Civil Engineering, Inner Mongolia University of Technology, Hohhot, 010051, People's Republic of China
| | - Tianjia Cheng
- School of Civil Engineering, Inner Mongolia University of Technology, Hohhot, 010051, People's Republic of China
| | - Runying Bai
- School of Civil Engineering, Inner Mongolia University of Technology, Hohhot, 010051, People's Republic of China
| | - Lei Song
- School of Civil Engineering, Inner Mongolia University of Technology, Hohhot, 010051, People's Republic of China
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17
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Cai M, Qian Z, Xiong X, Dong C, Song Z, Shi Y, Wei Z, Jin M. Cationic polyacrylamide (CPAM) enhanced pressurized vertical electro-osmotic dewatering of activated sludge. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 818:151787. [PMID: 34808190 DOI: 10.1016/j.scitotenv.2021.151787] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/07/2021] [Revised: 11/10/2021] [Accepted: 11/14/2021] [Indexed: 06/13/2023]
Abstract
Pressurized vertical electro-osmotic dewatering (PVEOD) has been regarded as a feasible method to achieve sludge deep-dewatering, but the dewatering efficiency is still challenged by high electric resistance. This study employed cationic polyacrylamide (CPAM) as a skeleton builder to enhance electro-osmotic flow in PVEOD. The sludge dewatering efficiency and synergistic effect of CPAM and PVEOD were elucidated. The sludge morphology, surface property, extracellular polymeric substances (EPS) destruction and migration, spatial distributions of proteins and polysaccharides, and current changes were investigated. After the addition of optimal CPAM dose, the sludge formed a uniform and porous structure that provided water channels and enhanced electric transport, thus promoting EPS destruction. The sludge moisture content (MC) analysis indicated the more liberation of bound water due to EPS destruction. Besides, the re-flocculation of disintegrated sludge flocs improved the sludge filtration and thus dewaterability. Instantaneous energy consumption (Et,0.5) was optimized and two-step synergistic mechanism was thus proposed. These findings indicated that the combination of CPAM and PVEOD is a promising strategy to broaden the scope of industrial application of sludge deep-dewatering.
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Affiliation(s)
- Meiqiang Cai
- School of Environmental Science and Engineering, Zhejiang Gongshang University, Hangzhou 310018, China
| | - Zhuohui Qian
- School of Environmental Science and Engineering, Zhejiang Gongshang University, Hangzhou 310018, China
| | - Xingaoyuan Xiong
- Centre for Water Technology (WATEC), Department of Biological and Chemical Engineering, Aarhus University, Universitetsbyen 36, 8000 Aarhus C, Denmark
| | - Chunying Dong
- School of Environmental Science and Engineering, Zhejiang Gongshang University, Hangzhou 310018, China.
| | - Zhijun Song
- School of Environmental Science and Engineering, Zhejiang Gongshang University, Hangzhou 310018, China
| | - Yuejing Shi
- School of Environmental Science and Engineering, Zhejiang Gongshang University, Hangzhou 310018, China
| | - Zongsu Wei
- Centre for Water Technology (WATEC), Department of Biological and Chemical Engineering, Aarhus University, Universitetsbyen 36, 8000 Aarhus C, Denmark
| | - Micong Jin
- Key Laboratory of Health Risk Appraisal for Trace Toxic Chemicals of Zhejiang Province, Ningbo Municipal Center for Disease Control and Prevention, Ningbo 315010, China; Ningbo Key Laboratory of Poison Research and Control, Ningbo Municipal Center for Disease Control and Prevention, Ningbo 315010, China
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18
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He L, Tong J, Yang Y, Wu J, Li L, Wei Z, Long W, Pang J, Shi J. Overestimate of remediation efficiency due to residual sodium persulfate in PAHs contaminated soil and a solution. J Environ Sci (China) 2022; 113:242-250. [PMID: 34963532 DOI: 10.1016/j.jes.2021.06.004] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2021] [Revised: 06/02/2021] [Accepted: 06/05/2021] [Indexed: 06/14/2023]
Abstract
Oxidation remediation is a commonly used technology for PAHs contaminated soil presently, but the overestimate of efficiency due to ongoing remediation by residual oxidants during extraction and testing has not been paid enough attention. In this study, persulfate was activated by Fe(II) to investigate the effects of residual oxidants on PAHs removal during detection process and the elimination effects of adding Na2SO3 and extending sampling time on residual oxidants. Results verified that the residual oxidants removed PAHs in extraction process, making the results lower than the actual values: the detection recovery rate η of ∑PAHs and 3-6 ring PAHs ranged from 24.3% (25% Na2S2O8 treatment) to 87.4% (5% Na2S2O8+4/4Fe2+ treatment), 20.1%-99.0%, 28.9%-87.9%, 20.8%-89.4%, and 18.6%-76.9%, respectively. After adding Na2SO3, the accuracy of detection results increased significantly: the η of ∑PAHs and 3-6 ring PAHs increased to 64.1%-96.5%, 58.8%-95.5%, 73.8%-114.4%, 60.6%-95.6%, and 45.4%-77.1%, respectively. After 49 days of adding oxidants, residual oxidants had no considerable effect on the detection of PAHs, indicating it was appropriate to start soil remediation verification sampling49 days after the remediation was completed. The observed results will help scientific evaluation of the remediation effects of chemical oxidation on organic contaminated soil.
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Affiliation(s)
- Liping He
- Yunnan Research Academy of Eco-environmental Sciences, Kunming 650034, China
| | - Jianhao Tong
- Department of Environmental Engineering, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058, China.
| | - Yuanqiang Yang
- Beijing Construction Engineering Group Environmental Remediation Co. Ltd., Beijing 100015, China
| | - Jianxun Wu
- Yunnan Research Academy of Eco-environmental Sciences, Kunming 650034, China
| | - Linqian Li
- Beijing Construction Engineering Group Environmental Remediation Co. Ltd., Beijing 100015, China
| | - Zhonghua Wei
- Yunnan Research Academy of Eco-environmental Sciences, Kunming 650034, China
| | - Wei Long
- Yunnan Research Academy of Eco-environmental Sciences, Kunming 650034, China
| | - Jingli Pang
- Department of Environmental Engineering, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058, China
| | - Jiyan Shi
- Department of Environmental Engineering, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058, China.
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19
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Hui K, Song L, Yin Z, Song H, Wang Z, Gao W, Xuan L. Freeze-thaw combined with activated carbon improves electrochemical dewaterability of sludge: analysis of sludge floc structure and dewatering mechanism. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2022; 29:20333-20346. [PMID: 34731422 DOI: 10.1007/s11356-021-16837-4] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/23/2021] [Accepted: 09/27/2021] [Indexed: 06/13/2023]
Abstract
Freeze-thaw (F/T) and electrochemistry both are environment-friendly and efficient sludge treatment technologies. In this study, the sludge samples were frozen at - 15 °C, and 20% g/gTss activated carbon (AC) was added to the dissolved sludge. Finally, the uniformly mixed sludge was treated at a voltage of 15 V for 25 min. During the experiment, the effect of F/T on the floc structure was analyzed by a laser particle analyzer and scanning electron microscope. F/T treatment improved the dewatering performance of the sludge and promoted the aggregation of sludge flocs into larger particles either. At the same time, the median diameter (D50) increased from 45.27 to 128.94 μm. AC was added to the thawed sludge solution before electrochemical treatment (EP). The conductivity of AC enhanced the effect of EP, thereby cracking the sludge flocs. Therefore, the three-dimensional excitation-emission matrix (3D-EEM) intensity of tightly bound extracellular polymeric substances (TB-EPS) decreased significantly. The protein in TB-EPS decreased from 54 to 33%, and the D50 was also reduced to 105.3 μm. The final specific resistance of filtration and water content were reduced by 96.39% and 32.17%, respectively. The dehydrated cake elemental analysis showed that increased AC improved the sludge cake's combustion efficiency significantly. Moreover, the preliminary economic analysis indicated that the cost of this research was low, which implied the potential application value of combined treatment.
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Affiliation(s)
- Kai Hui
- School of Civil Engineering, Inner Mongolia University of Technology, Hohhot, 010051, China
| | - Lei Song
- School of Civil Engineering, Inner Mongolia University of Technology, Hohhot, 010051, China.
| | - Zhenzhou Yin
- School of Civil Engineering, Inner Mongolia University of Technology, Hohhot, 010051, China
| | - Hongwei Song
- School of Civil Engineering, Inner Mongolia University of Technology, Hohhot, 010051, China
| | - Zehao Wang
- School of Civil Engineering, Inner Mongolia University of Technology, Hohhot, 010051, China
| | - Wenjian Gao
- School of Civil Engineering, Inner Mongolia University of Technology, Hohhot, 010051, China
| | - Lili Xuan
- School of Civil Engineering, Inner Mongolia University of Technology, Hohhot, 010051, China
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20
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Bai L, Wang G, Ge D, Dong Y, Wang H, Wang Y, Zhu N, Yuan H. Enhanced waste activated sludge dewaterability by the ozone-peroxymonosulfate oxidation process: Performance, sludge characteristics, and implication. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 807:151025. [PMID: 34662606 DOI: 10.1016/j.scitotenv.2021.151025] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/20/2021] [Revised: 09/28/2021] [Accepted: 10/12/2021] [Indexed: 06/13/2023]
Abstract
Dewatering treatment is an essential step to diminish sludge volume, cut down transportation costs, and improve subsequent disposal efficiency. In this study, ozone-peroxymonosulfate (O3/PMS) oxidation process was employed to ameliorate sludge dewaterability. Sludge capillary suction time (CST) and water content (Wc) of dewatered sludge cake could reduce from 70.5 s and 81.93% to 26.7 s and 65.65%, respectively, under the optimal dosage of 30 mg/g TS O3 and 0.4 mmol/g TS PMS. The increased sludge zeta potential, particle size, and fluidity promoted sludge dewatering performance apparently. The decreased hydrophilic, fluorescent EPS components and proteins/peptides-like + Lipids percentage in EPS as well as the ratio of α-helix/(β-sheet + random coil) of treated EPS protein secondary structure was greatly responsible for the enhanced sludge dewaterability. SO4- and OH were detected in ozone-peroxymonosulfate process to crack sludge flocs, eliminate hydrophilic substances and liberate bound water. Moreover, the concentrations of both heavy metals and polycyclic aromatic hydrocarbons (PAHs) of sludge after O3/PMS conditioning were decreased, and the stability and toxicity of heavy metals were also reduced, except Zn. In conclusion, this work offered a comprehensive insight based on ozone-peroxymonosulfate (O3/PMS) advanced oxidation for improving the sludge dewaterability and environmental implication.
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Affiliation(s)
- Lu Bai
- Shanghai Engineering Research Center of Solid Waste Treatment and Resource Recovery, School of Environmental Science & Engineering, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Guanjun Wang
- Shanghai Engineering Research Center of Solid Waste Treatment and Resource Recovery, School of Environmental Science & Engineering, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Dongdong Ge
- Shanghai Engineering Research Center of Solid Waste Treatment and Resource Recovery, School of Environmental Science & Engineering, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Yanting Dong
- Shanghai Engineering Research Center of Solid Waste Treatment and Resource Recovery, School of Environmental Science & Engineering, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Hui Wang
- Shanghai Engineering Research Center of Solid Waste Treatment and Resource Recovery, School of Environmental Science & Engineering, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Yuhui Wang
- Shanghai Engineering Research Center of Solid Waste Treatment and Resource Recovery, School of Environmental Science & Engineering, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Nanwen Zhu
- Shanghai Engineering Research Center of Solid Waste Treatment and Resource Recovery, School of Environmental Science & Engineering, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Haiping Yuan
- Shanghai Engineering Research Center of Solid Waste Treatment and Resource Recovery, School of Environmental Science & Engineering, Shanghai Jiao Tong University, Shanghai 200240, China.
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21
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Wang G, Ge D, Bai L, Dong Y, Bian C, Xu J, Zhu N, Yuan H. Insight into the roles of electrolysis-activated persulfate oxidation in the waste activated sludge dewaterability: Effects and mechanism. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2021; 297:113342. [PMID: 34314959 DOI: 10.1016/j.jenvman.2021.113342] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/28/2021] [Revised: 07/12/2021] [Accepted: 07/18/2021] [Indexed: 06/13/2023]
Abstract
Sludge dewatering, as one of the most important steps of sludge treatment, can facilitate transportation and improve disposal efficiency by reducing the volume of sludge. This study investigated the effects of electrolysis-activated persulfate oxidation on improving sludge dewaterability. The results indicated that the sludge capillary suction time (CST) and water content of dewatered sludge cake (Wc) reduced from 93.7 s and 87.8% to 9.7 s and 68.3% respectively at the optimized process parameters: electrolysis voltage of 40 V, electrolysis time of 20 min, and 1.2 mmol/g TS S2O82-. Correlation analysis revealed that the enhancement of sludge dewaterability was closely associated with the increased floc size and zeta potential, decreased protein content in three-layers extracellular polymeric substances (EPS) and viscosity (R = -0.868, p = 0.002; R = -0.703, p = 0.035; R ≥ 0.961, p < 0.001; R = 0.949, p < 0.001). Four protein fluorescence regions in EPS were analyzed by three-dimensional excitation-emission matrix parallel factor (3D-EEM-PARAFAC). The protein secondary structure was changed after the treatment, and the reduction of α-helix/(β-sheet + random coil) indicated that more hydrophobic sites were exposed. Analysis by X-ray photoelectron spectroscopy (XPS), Fourier transform infrared (FTIR) and rheological test demonstrated that the hydrophilic functional groups of the sludge were decreased and the sludge mobility was significantly enhanced after the treatment with electrolysis-activated persulfate oxidation. Moreover, bound water was converted to free water during SO4·- and ·OH generated by electrolysis-activated persulfate degraded EPS and attacked sludge cells. Meanwhile, scanning electron microscopy (SEM) images revealed that the treated sludge formed porous channel structures, which promoted the flowability of the water. These findings provide a new insight based on electrolysis-activated persulfate oxidation in sludge treatment for enhancing sludge dewaterability.
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Affiliation(s)
- Guanjun Wang
- Shanghai Engineering Research Center of Solid Waste Treatment and Resource Recovery, School of Environmental Science & Engineering, Shanghai Jiao Tong University, Shanghai, 200240, China
| | - Dongdong Ge
- Shanghai Engineering Research Center of Solid Waste Treatment and Resource Recovery, School of Environmental Science & Engineering, Shanghai Jiao Tong University, Shanghai, 200240, China
| | - Lu Bai
- Shanghai Engineering Research Center of Solid Waste Treatment and Resource Recovery, School of Environmental Science & Engineering, Shanghai Jiao Tong University, Shanghai, 200240, China
| | - Yanting Dong
- Shanghai Engineering Research Center of Solid Waste Treatment and Resource Recovery, School of Environmental Science & Engineering, Shanghai Jiao Tong University, Shanghai, 200240, China
| | - Chang Bian
- Shanghai Engineering Research Center of Solid Waste Treatment and Resource Recovery, School of Environmental Science & Engineering, Shanghai Jiao Tong University, Shanghai, 200240, China
| | - Jiajia Xu
- Shanghai Engineering Research Center of Solid Waste Treatment and Resource Recovery, School of Environmental Science & Engineering, Shanghai Jiao Tong University, Shanghai, 200240, China
| | - Nanwen Zhu
- Shanghai Engineering Research Center of Solid Waste Treatment and Resource Recovery, School of Environmental Science & Engineering, Shanghai Jiao Tong University, Shanghai, 200240, China
| | - Haiping Yuan
- Shanghai Engineering Research Center of Solid Waste Treatment and Resource Recovery, School of Environmental Science & Engineering, Shanghai Jiao Tong University, Shanghai, 200240, China.
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