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Yu H, Wang X, Chen Y, He Y, Yang S, Yuan H, Tao H, Xu S, Gu L. Advanced application of tea residue extracts rich in polyphenols for enhancing sludge dewaterability: Unraveling the role of pH regulation. ENVIRONMENTAL RESEARCH 2024; 252:118978. [PMID: 38704012 DOI: 10.1016/j.envres.2024.118978] [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: 02/03/2024] [Revised: 04/07/2024] [Accepted: 04/19/2024] [Indexed: 05/06/2024]
Abstract
Tea polyphenols (TPs), as a kind of derivatives from tea waste, were employed as a novel environmentally friendly bio-based sludge conditioner in this study. The findings showed that when TPs were applied at a dosage of 300 mg g-1 DS, the sludge CST0/CST ratio significantly increased to 1.90. pH regulation was found to markedly affect the dewatering efficiency of sludge. At pH 4, the CST0/CST rose to 2.86, coupled with a reduction in the specific resistance to filtration (SRF) from 6.69 × 1013 m kg-1 to 1.43 × 1013 m kg-1 and a decrease in the moisture content (MC) from 90.57% to 68.75%. TPs formed complexes and precipitated sludge proteins, as demonstrated by changes in the extracellular polymeric substances (EPS), viscosity, zeta potential, and particles size distribution. The optimization significance of acidification treatment on sludge structure disintegration, the interaction of TPs with EPS, and the removal of sludge proteins were elucidated. The research provided an ideal approach for the integrated utilization of biomass resources from tea waste and highlighted the potential application of TPs as an environmentally friendly conditioner in sludge dewatering.
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Affiliation(s)
- Haixiang Yu
- School of Environment and Architecture, University of Shanghai for Science and Technology, Shanghai, 200093, PR China.
| | - Xin Wang
- School of Environment and Architecture, University of Shanghai for Science and Technology, Shanghai, 200093, PR China
| | - Ya Chen
- Shanghai Chengtou Raw Water Co., LTD, Shanghai, 200125, PR China
| | - Yiyang He
- School of Environment and Architecture, University of Shanghai for Science and Technology, Shanghai, 200093, PR China
| | - Siting Yang
- School of Environment and Architecture, University of Shanghai for Science and Technology, Shanghai, 200093, PR China
| | - Haiping Yuan
- School of Environment Engineering, Shanghai Jiao Tong University, Shanghai, 200240, PR China
| | - Hong Tao
- School of Environment and Architecture, University of Shanghai for Science and Technology, Shanghai, 200093, PR China
| | - Suyun Xu
- 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.
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2
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Dai Q, Liu Z, Li H, Zhang R, Cai T, Yin J, Gao Y, Li S, Lu X, Zhen G. Enhanced dewaterability and triclosan removal of waste activated sludge with iron-rich mineral-activated peroxymonosulfate. WASTE MANAGEMENT (NEW YORK, N.Y.) 2024; 182:271-283. [PMID: 38688046 DOI: 10.1016/j.wasman.2024.04.037] [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: 02/07/2024] [Revised: 03/29/2024] [Accepted: 04/21/2024] [Indexed: 05/02/2024]
Abstract
High water and pharmaceutical and care products (PPCPs) bounded in sludge flocs limit its utilization and disposal. The advanced oxidation process of perxymonosulfate (PMS) catalyzed by iron salts has been widely used in sludge conditioning. In this study, two iron-rich minerals pyrite and siderite were proposed to enhance sludge dewatering performance and remove the target contaminant of triclosan (TCS). The permanent release of Fe2+ in the activation of PMS made siderite more effective in enhancing sludge dewater with capillary suction time (CST) diminishing by 60.5 %, specific resistance to filtration (SRF) decreasing by 79.2 %, and bound water content (BWC) dropping from 37.1 % to 2.6 % at siderite/PMS dosages of 0.36/0.20 mmol/g-TSS after 20 min of pretreatment. Pyrite/PMS performed slightly inferior under the same conditions and the corresponding CST and SRF decreased by 51.5 % and 71.8 % while the BWC only declined to 17.8 %. Rheological characterization was employed to elucidate the changes in sludge dewatering performance, with siderite/PMS treated sludge showing a 48.3 % reduction in thixotropy, higher than 28.4 % of pyrite/PMS. Oscillation and creep tests further demonstrated the significantly weakened viscoelastic behavior of the sludge by siderite/PMS pretreatment. For TCS mineralization removal, siderite/PMS achieved a high removal efficiency of 43.9 %, in comparison with 39.9 % for pyrite/PMS. The reduction in the sludge solids phase contributed the most to the TCS removal. Free radical quenching assays and EPR spectroscopy showed that both siderite/PMS and pyrite/PMS produced SO4-· and ·OH, with the latter acting as the major radicals. Besides, the dosage of free radicals generated from siderite/PMS exhibited a lower time-dependence, which also allowed it to outperform in destroying EPS matrix, neutralizing the negative Zeta potential of sludge flocs, and mineralizing macromolecular organic matter.
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Affiliation(s)
- Qicai Dai
- Shanghai Key Lab for Urban Ecological Processes and Eco-Restoration, School of Ecological and Environmental Sciences, East China Normal University, Shanghai 200241, China
| | - Zhaobin Liu
- Shanghai Key Lab for Urban Ecological Processes and Eco-Restoration, School of Ecological and Environmental Sciences, East China Normal University, Shanghai 200241, China
| | - Huan Li
- Shanghai Key Lab for Urban Ecological Processes and Eco-Restoration, School of Ecological and Environmental Sciences, East China Normal University, Shanghai 200241, China
| | - Ruiliang Zhang
- Shanghai Key Lab for Urban Ecological Processes and Eco-Restoration, School of Ecological and Environmental Sciences, East China Normal University, Shanghai 200241, China
| | - Teng Cai
- Shanghai Key Lab for Urban Ecological Processes and Eco-Restoration, School of Ecological and Environmental Sciences, East China Normal University, Shanghai 200241, China
| | - Jian Yin
- Shanghai Key Lab for Urban Ecological Processes and Eco-Restoration, School of Ecological and Environmental Sciences, East China Normal University, Shanghai 200241, China
| | - Yijing Gao
- Shanghai Key Lab for Urban Ecological Processes and Eco-Restoration, School of Ecological and Environmental Sciences, East China Normal University, Shanghai 200241, China
| | - Siqin Li
- Shanghai Key Lab for Urban Ecological Processes and Eco-Restoration, School of Ecological and Environmental Sciences, East China Normal University, Shanghai 200241, China
| | - Xueqin Lu
- Shanghai Key Lab for Urban Ecological Processes and Eco-Restoration, School of Ecological and Environmental Sciences, East China Normal University, Shanghai 200241, China; Shanghai Engineering Research Center of Biotransformation of Organic Solid Waste, Shanghai 200241, China
| | - Guangyin Zhen
- Shanghai Key Lab for Urban Ecological Processes and Eco-Restoration, School of Ecological and Environmental Sciences, East China Normal University, Shanghai 200241, China; Shanghai Institute of Pollution Control and Ecological Security, 1515 North Zhongshan Rd. (No. 2), Shanghai 200092, China; Shanghai Engineering Research Center of Biotransformation of Organic Solid Waste, Shanghai 200241, China; Technology Innovation Center for Land Spatial Eco-restoration in Metropolitan Area, Ministry of Natural Resources, 3663 N. Zhongshan Road, Shanghai, 200062, China.
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3
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Xiong Y, Lai J, Liu Z, Song M. Synergetic conditioning via oxalic acid enhanced Fe 2+/CaO 2 and skeleton construct to achieve deep dewatering of sewage sludge. CHEMOSPHERE 2024; 358:142115. [PMID: 38657689 DOI: 10.1016/j.chemosphere.2024.142115] [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: 12/28/2023] [Revised: 03/17/2024] [Accepted: 04/21/2024] [Indexed: 04/26/2024]
Abstract
Extracellular polymeric substance (EPS) with highly hydrophilic groups and sludge with high compressibility are determined sludge dewaterability. Herein, Fe2+ catalyzed calcium peroxide (CaO2) assisted by oxalic acid (OA) Fenton-like process combined with coal slime was applied to improve sludge dewaterability. Results demonstrated that the sludge treated by 0.45/1/1.1-OA/Fe2+/CaO2 mM/g DS, the water content (WC), specific resistance to filtration and capillary suction time dropped to 53.01%, 24.3 s and 1.2 × 1012 m/kg, respectively. Under coal slime ratio as 0.6, WC and compressibility were further reduced to 42.72% and 0.66, respectively. The hydroxyl radicals generated by OA/Fe2+/CaO2 under near-neutral pH layer by layer collapsed EPS, resulting in the degradation and migration of inner releasing components and the exposure of inner sludge flocs skeleton. The hydrophilic tryptophan-like protein of TB-EPS were degraded into aromatic protein of S-EPS and exposed inner hydrophobic sites. The protein secondary structures were transformed by destroying hydrophilic functional groups, which were attributed to the reducing α-helix ratio and reconstructing β-sheet. Moreover, coal slime as the skeleton builder lowered compressibility and formed more macropores to increase the filterability of pre-oxidized sludge for the higher intensity of rigid substances. This study deepened the understanding of OA enhanced Fenton-like system effects on sludge dewaterability and proposed a cost-effective and synergistic waste treatment strategy in sludge dewatering.
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Affiliation(s)
- Yun Xiong
- 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
| | - 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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Liu M, Rashid S, Wang W, Zhang H, Zhao Y, Fu X, Su Z, Graham N, Yu W. The application of chitosan quaternary ammonium salt to replace polymeric aluminum ferric chloride for sewage sludge dewatering. WATER RESEARCH 2024; 256:121539. [PMID: 38583335 DOI: 10.1016/j.watres.2024.121539] [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: 02/05/2024] [Revised: 03/26/2024] [Accepted: 03/27/2024] [Indexed: 04/09/2024]
Abstract
Inorganic coagulants such as poly aluminum ferric chloride (Al/Fe) are applied conventionally to sewage sludge dewatering and can be retained in the sludge cake, causing its conductivity to increase and generate secondary pollution. To reduce these disadvantages, there is a need to develop alternative, more sustainable chemicals as substitutes for conventional inorganic coagulants. In the present investigation, the application of a polymeric chitosan quaternary ammonium salt (CQAS) is explored as a complete, or partial, replacement for Al/Fe in the context of sludge dewatering processes. Laboratory experiments using digested sewage sludge showed that CQAS could effectively substitute for over 80 % of the Al/Fe inorganic coagulant in the sludge dewatering process. This substitution resulted in a reduction of sludge cake conductivity by more than 50 %. Simulation of sludge dewatering curves and imaging of the sludge surface indicated that the addition of CQAS led to an increase in nanosized pores, and a decrease in the specific resistance of the sludge filter cake as the dosage of Al/Fe decreased to around 30 %. The variations of fluorescence emission, quantum yield and carboxylic and amino groups, suggested that the chelating of Al/Fe decreased due to the bridging effects of CQAS. The CQAS had different flocculation bridging effects on various EPS fractions, which varied the amount of protein chelated with Al/Fe in each fraction. This study provides new information about the benefits of replacing conventional inorganic coagulants with natural organic polymers for sewage sludge dewatering, in terms of reduced sludge cake conductivity and greater dry solids content.
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Affiliation(s)
- Minmin Liu
- Key Laboratory of Drinking Water Science and Technology, Research Centre for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
| | - Sajid Rashid
- Key Laboratory of Drinking Water Science and Technology, Research Centre for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
| | - Wei Wang
- Engineering Technology Research Center for Municipal Wastewater Reclamation, R&D Center, Beijing Drainage Group Co., Ltd., Beijing 100124, China
| | - Huihui Zhang
- Engineering Technology Research Center for Municipal Wastewater Reclamation, R&D Center, Beijing Drainage Group Co., Ltd., Beijing 100124, China
| | - Yawei Zhao
- Engineering Technology Research Center for Municipal Wastewater Reclamation, R&D Center, Beijing Drainage Group Co., Ltd., Beijing 100124, China
| | - Xingmin Fu
- Engineering Technology Research Center for Municipal Wastewater Reclamation, R&D Center, Beijing Drainage Group Co., Ltd., Beijing 100124, China
| | - Zhaoyang Su
- Key Laboratory of Drinking Water Science and Technology, Research Centre for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
| | - Nigel Graham
- Department of Civil and Environmental Engineering, Imperial College London, South Kensington Campus, London SW7 2AZ, United Kingdom
| | - Wenzheng Yu
- Key Laboratory of Drinking Water Science and Technology, Research Centre for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China.
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Liu Z, Heng S, Dai Q, Gao Y, Han Y, Hu L, Liu Y, Lu X, Zhen G. Simultaneous removal of antibiotic resistance genes and improved dewatering ability of waste activated sludge by Fe(II)-activated persulfate oxidation. WATER RESEARCH 2024; 253:121265. [PMID: 38340701 DOI: 10.1016/j.watres.2024.121265] [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: 12/20/2023] [Revised: 01/21/2024] [Accepted: 02/04/2024] [Indexed: 02/12/2024]
Abstract
Waste activated sludge properties vary widely with different regions due to the difference in living standards and geographical distribution, making a big challenge to developing a universally effective sludge dewatering technique. The Fe(II)-activated persulfate (S2O82-) oxidation process shows excellent ability to disrupt sludge cells and extracellular polymeric substances (EPS), and release bound water from sludge flocs. In this study, the discrepancies in the physicochemical characteristics of sludge samples from seven representative cities in China (e.g., dewaterability, EPS composition, surface charge, microbial community, relative abundance of antibiotic resistance genes (ARGs), etc.) were investigated, and the role of Fe(II)-S2O82- oxidation in enhancing removal of antibiotic resistance genes and dewatering ability were explored. The results showed significant differences between the EPS distribution and chemical composition of sludge samples due to different treatment processes, effluent sources, and regions. The Fe(II)-S2O82- oxidation pretreatment had a good enhancement of sludge dewatering capacity (up to 76 %). Microbial analysis showed that the microbial community in each sludge varied significantly depending on the types of wastewater, the wastewater treatment processes, and the regions, but Fe(II)-S2O82- oxidation was able to attack and rupture the sludge zoogloea indiscriminately. Genetic analysis further showed that a considerable number of ARGs were detected in all of these sludge samples and that Fe(II)-S2O82- oxidation was effective in removing ARGs by higher than 90 %. The highly active radicals (e.g., SO4-·, ·OH) produced in this process caused drastic damage to sludge microbial cells and DNA stability while liberating the EPS/cell-bound water. Co-occurrence network analysis highlighted a positive correlation between population distribution and ARGs abundance, while variations in microbial communities were linked to regional differences in living standards and level of economic development. Despite these variations, the Fe(II)-S2O82- oxidation consistently achieved excellent performance in both ARGs removal and sludge dewatering. The significant modularity of associations between different microbial communities also confirms its ability to reduce horizontal gene transfer (HGT) by scavenging microbes.
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Affiliation(s)
- Zhaobin Liu
- Shanghai Key Lab for Urban Ecological Processes and Eco-Restoration, School of Ecological and Environmental Sciences, East China Normal University, Shanghai 200241, China
| | - Shiliang Heng
- Shanghai Key Lab for Urban Ecological Processes and Eco-Restoration, School of Ecological and Environmental Sciences, East China Normal University, Shanghai 200241, China
| | - Qicai Dai
- Shanghai Key Lab for Urban Ecological Processes and Eco-Restoration, School of Ecological and Environmental Sciences, East China Normal University, Shanghai 200241, China
| | - Yijing Gao
- Shanghai Key Lab for Urban Ecological Processes and Eco-Restoration, School of Ecological and Environmental Sciences, East China Normal University, Shanghai 200241, China
| | - Yule Han
- Shanghai Key Lab for Urban Ecological Processes and Eco-Restoration, School of Ecological and Environmental Sciences, East China Normal University, Shanghai 200241, China
| | - Lingtian Hu
- Shanghai Key Lab for Urban Ecological Processes and Eco-Restoration, School of Ecological and Environmental Sciences, East China Normal University, Shanghai 200241, China
| | - Yisheng Liu
- Shanghai Key Lab for Urban Ecological Processes and Eco-Restoration, School of Ecological and Environmental Sciences, East China Normal University, Shanghai 200241, China
| | - Xueqin Lu
- Shanghai Key Lab for Urban Ecological Processes and Eco-Restoration, School of Ecological and Environmental Sciences, East China Normal University, Shanghai 200241, China; Shanghai Engineering Research Center of Biotransformation of Organic Solid Waste, Shanghai 200241, PR China; Institute of Eco-Chongming (IEC), 3663N. Zhongshan Rd., Shanghai 200062, China
| | - Guangyin Zhen
- Shanghai Key Lab for Urban Ecological Processes and Eco-Restoration, School of Ecological and Environmental Sciences, East China Normal University, Shanghai 200241, China; Shanghai Engineering Research Center of Biotransformation of Organic Solid Waste, Shanghai 200241, PR China; Shanghai Institute of Pollution Control and Ecological Security, 1515 North Zhongshan Rd. (No. 2), Shanghai 200092, PR China; Technology Innovation Center for Land Spatial Eco-restoration in Metropolitan Area, Ministry of Natural Resources, 3663N. Zhongshan Road, Shanghai 200062, China.
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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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Ajmal M, Shao Y, Huo W, Lu W. Deep-dewatering of sewage sludge using double dielectric barrier discharge (DDBD) plasma technology. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 912:168887. [PMID: 38016553 DOI: 10.1016/j.scitotenv.2023.168887] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/04/2023] [Revised: 11/12/2023] [Accepted: 11/23/2023] [Indexed: 11/30/2023]
Abstract
Deep dewatering of sewage sludge is essential for optimizing disposal and resource recovery. This study explores the potential of Double Dielectric Barrier Discharge (DDBD) plasma for enhancing waste activated sludge (WAS) dewatering. Key operational parameters (applied voltage, treatment duration, and air feeding rate) were systematically investigated using a two-step approach: Single Factor-at-a-Time (SFAT) and central composite design (CCD) within the response surface methodology (RSM) framework. The aim was to identify influential factors and their optimal settings for maximizing dewatering efficiency while minimizing energy usage. Higher applied voltages (30 kV) and longer treatment durations (40 min) notably improved % moisture reduction (%MR) (92.92 % and 94.35 %, respectively). ANOVA analysis emphasized the equal and substantial impact of applied voltage and treatment duration on %MR and energy efficiency (EE), whereas the air feeding rate exhibited no significant effect. However, it's worth noting that %MR and EE did not display a strictly linear relationship, suggesting complex interactions. Furthermore, two soft sensing models were developed: a quadratic model for %MR and a linear model for energy efficiency (EE). Results showed minimal reductions in TOC content, maintaining values between 13.68 % and 14.28 % compared to untreated sludge 14.37 %. The study also revealed that ROS generated by DDBD plasma played a key role in sludge disintegration, as observed through SEM and FTIR, enhancing dewatering efficiency by the destruction of sludge flocs and the transformation of organic substances. In conclusion, DDBD plasma technology offers a sustainable solution for effective sludge dewatering in WWTPs, preserving organic content.
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Affiliation(s)
- Muhammad Ajmal
- School of Environment, Tsinghua University, Beijing 100084, China
| | - Yuchao Shao
- School of Environment, Tsinghua University, Beijing 100084, China
| | - Weizhong Huo
- School of Environment, Tsinghua University, Beijing 100084, China
| | - Wenjing Lu
- School of Environment, Tsinghua University, Beijing 100084, China.
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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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9
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Sari Erkan H, Bakaraki Turan N. Effects of hydrogen peroxide and calcium hypochlorite on chemical oxygen demand solubilization and disintegration of waste activated sludge by electro-chemical pretreatment. ENVIRONMENTAL TECHNOLOGY 2024; 45:508-522. [PMID: 35993109 DOI: 10.1080/09593330.2022.2114856] [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: 11/19/2021] [Accepted: 08/03/2022] [Indexed: 05/16/2023]
Abstract
ABSTRACTThe combination of electrochemical (EC) pretreatment with hydrogen peroxide (HP) and calcium hypochlorite (CHC) was investigated in this study for their effect on soluble chemical oxygen demand (CODs) and disintegration degree (DD) of waste activated sludge (WAS). For this aim, response surface methodology (RSM) and Box-Behnken design (BBD) were applied the determination of the optimum operational conditions. Operational conditions were varied between 0.2 and 2.0 mmol/g SS for HP and CHC dosages, 1-5 A for the applied current, 2-10 for the initial pH, and 15-45 min for the treatment time. Obtained results for each treatment were accurate and significant with correlation coefficients (R2) of 0.8639% and 0.9189% for EC combined with HP pretreatment and EC combined with CHC pretreatment, respectively. According to the obtained results, CODs increased in comparison to the raw sludge (168 mg/L) noting that CODs for EC - CHC (1155 ± 21 mg/L) was higher than EC - HP (811.5 ± 15 mg/L) at optimized conditions (for EC-HP pretreatment: HP dosage: 0.34 mmol/g TSS, Applied current:5 A, Initial pH:10, Time: 45 min, For EC-CHC pretreatment: CHC dosage: 0.23 mmol/g TSS, Applied current:4.83 A, Initial pH:10, Time: 40 min). Besides, the DD in terms of COD, total nitrogen (TN) and total organic carbon (TOC) (DDCOD, DDTN and DDTOC) registered increased values after the application of the EC treatment with both oxidants. The highest DDCOD, DDTN and DDTOC values were obtained with EC-CHC pretreatment for 11.34%, 20.34% and 9.18% respectively compared to EC-HP pretreatment (DDCOD: 7.37%, DDTN: 15.18% and DDTOC: 6.94%).
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Affiliation(s)
- Hanife Sari Erkan
- Civil Engineering Faculty, Environmental Engineering Department, Yildiz Technical University, Istanbul, Turkey
| | - Nouha Bakaraki Turan
- Civil Engineering Faculty, Environmental Engineering Department, Yildiz Technical University, Istanbul, Turkey
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10
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Xie J, Yang C, Li X, Wu S, Lin Y. Generation and engineering applications of sulfate radicals in environmental remediation. CHEMOSPHERE 2023; 339:139659. [PMID: 37506891 DOI: 10.1016/j.chemosphere.2023.139659] [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: 06/10/2023] [Revised: 07/20/2023] [Accepted: 07/25/2023] [Indexed: 07/30/2023]
Abstract
Sulfate radical (SO4•-)-based advanced oxidation processes (AOPs) have become promising alternatives in environmental remediation due to the higher redox potential (2.6-3.1 V) and longer half-life period (30-40 μs) of sulfate radicals compared with many other radicals such as hydroxyl radicals (•OH). The generation and mechanisms of SO4•- and the applications of SO4•--AOPs have been examined extensively, while those using sulfite as activation precursor and their comparisons among various activation precursors have rarely reviewed comprehensively. In this article, the latest progresses in SO4•--AOPs were comprehensively reviewed and commented on. First of all, the generation of SO4•- was summarized via the two activation methods using various oxidant precursors, and the generation mechanisms were also presented, which provides a reference for guiding researchers to better select two precursors. Secondly, the reaction mechanisms of SO4•- were reviewed for organic pollutant degradation, and the reactivity was systematically compared between SO4•- and •OH. Thirdly, methods for SO4•- detection were reviewed which include quantitative and qualitative ones, over which current controversies were discussed. Fourthly, the applications of SO4•--AOPs in various environmental remediation were summarized, and the advantages, challenges, and prospects were also commented. At last, future research needs for SO4•--AOPs were also proposed consequently. This review could lead to better understanding and applications of SO4•--AOPs in environmental remediations.
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Affiliation(s)
- Jun Xie
- College of Environmental Science and Engineering, Hunan University and Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Changsha, Hunan, 410082, China
| | - Chunping Yang
- College of Environmental Science and Engineering, Hunan University and Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Changsha, Hunan, 410082, China; Academy of Environmental and Resource Sciences, School of Environmental Science and Engineering, Guangdong University of Petrochemical Technology, Maoming, Guangdong, 525000, China; School of Environmental and Chemical Engineering, Nanchang Hangkong University, Nanchang, Jiangxi, 330063, China.
| | - Xiang Li
- Academy of Environmental and Resource Sciences, School of Environmental Science and Engineering, Guangdong University of Petrochemical Technology, Maoming, Guangdong, 525000, China
| | - Shaohua Wu
- Academy of Environmental and Resource Sciences, School of Environmental Science and Engineering, Guangdong University of Petrochemical Technology, Maoming, Guangdong, 525000, China.
| | - Yan Lin
- College of Environmental Science and Engineering, Hunan University and Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Changsha, Hunan, 410082, China
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11
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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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12
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Zhu Y, Xiao K, Ou B, Liu Y, Yu W, Jian S, Hu X, Liu H, Lei P, Yang J. Behavior of organic components and the migration of heavy metals during sludge dewatering by different advanced oxidation processes via optical spectroscopy and molecular fingerprint analysis. WATER RESEARCH 2023; 243:120336. [PMID: 37454458 DOI: 10.1016/j.watres.2023.120336] [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: 01/19/2023] [Revised: 07/04/2023] [Accepted: 07/08/2023] [Indexed: 07/18/2023]
Abstract
A comparative study of the different advanced oxidation processes (Fe(II)-Oxone, Fe(II)-H2O2, and Fe(II)-NaClO) was carried out herein to analyze the characteristics of organic components and the migration of heavy metals in waste activated sludge. With the Fe(II)-Oxone and Fe(II)-H2O2 treatments, sludge dewaterability was significantly improved, however, sludge dewaterability was deteriorated by the Fe(II)-NaClO treatment. The enhanced sludge dewaterability by the Fe(II)-Oxone and Fe(II)-H2O2 treatments was strongly correlated with the shifted organic components, particularly proteins, in soluble extracellular polymeric substances (S-EPS), while the deteriorated sludge dewaterability by the Fe(II)-NaClO treatment was strongly correlated with the over release of organic components from bound EPS (B-EPS) to S-EPS. For both the Fe(II)-Oxone and Fe(II)-H2O2 treatments, the radicals preferentially attacked humic acid-like organic components over the protein-like organic components in S-EPS, while for the Fe(II)-NaClO treatment, interestingly, the radicals preferentially attacked the protein-like organic components in both S-EPS and B-EPS. The hydrophilic functional groups like phenolic OH and CO of polysaccharides may be more preferentially migrated to S-EPS of sludge by the Fe(II)-NaClO treatment compared to the other two treatments. With the Fe(II)-Oxone and Fe(II)-H2O2 treatments, the proportion of aliphatic compounds as well as the much oxygenated organic components with a low desaturation and a low molecular weight increased. While with the Fe(II)-NaClO treatment, the proportion of low oxygenated organic components with a high desaturation and a high molecular weight increased. The concentration of total organic carbon, particularly the concentration of proteins, may be the key factor determining the shift of Zn and Cu from sludge solid to liquid phase, along with the high oxidation extent of organic components and close binding to CHOS and CHON compounds as indicated by density functional theory (DFT) calculation. This study systematically revealed the simultaneous sludge dewatering and migration of heavy metals when the role of organic components was factored into herein.
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Affiliation(s)
- Yuwei Zhu
- School of Environmental Science & Engineering, Huazhong University of Science and Technology, Luoyu Road 1037, Wuhan, Hubei 430074, China; Hubei Provincial Engineering Laboratory for Solid Waste Treatment Disposal and Recycling, Luoyu Road 1037, Wuhan, Hubei 430074, China
| | - Keke Xiao
- School of Environmental Science & Engineering, Huazhong University of Science and Technology, Luoyu Road 1037, Wuhan, Hubei 430074, China; Hubei Provincial Engineering Laboratory for Solid Waste Treatment Disposal and Recycling, Luoyu Road 1037, Wuhan, Hubei 430074, China.
| | - Bei Ou
- School of Environmental Science & Engineering, Huazhong University of Science and Technology, Luoyu Road 1037, Wuhan, Hubei 430074, China; Hubei Provincial Engineering Laboratory for Solid Waste Treatment Disposal and Recycling, Luoyu Road 1037, Wuhan, Hubei 430074, China
| | - Yuan Liu
- School of Environmental Science & Engineering, Huazhong University of Science and Technology, Luoyu Road 1037, Wuhan, Hubei 430074, China; Hubei Provincial Engineering Laboratory for Solid Waste Treatment Disposal and Recycling, Luoyu Road 1037, Wuhan, Hubei 430074, China
| | - Wenbo Yu
- School of Environmental Science & Engineering, Huazhong University of Science and Technology, Luoyu Road 1037, Wuhan, Hubei 430074, China; Hubei Provincial Engineering Laboratory for Solid Waste Treatment Disposal and Recycling, Luoyu Road 1037, Wuhan, Hubei 430074, China
| | - Sifeng Jian
- Central & Southern China Municipal Engineering Design and Research Institute Co., Ltd., Wuhan, Hubei 430010, China
| | - Xinli Hu
- Central & Southern China Municipal Engineering Design and Research Institute Co., Ltd., Wuhan, Hubei 430010, China
| | - Haiyan Liu
- Central & Southern China Municipal Engineering Design and Research Institute Co., Ltd., Wuhan, Hubei 430010, China
| | - Peishu Lei
- Central & Southern China Municipal Engineering Design and Research Institute Co., Ltd., Wuhan, Hubei 430010, China
| | - Jiakuan Yang
- School of Environmental Science & Engineering, Huazhong University of Science and Technology, Luoyu Road 1037, Wuhan, Hubei 430074, China; Hubei Provincial Engineering Laboratory for Solid Waste Treatment Disposal and Recycling, Luoyu Road 1037, Wuhan, Hubei 430074, China; State Key Laboratory of Coal Combustion, Huazhong University of Science and Technology, Luoyu Road 1037, Wuhan, Hubei 430074, China
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13
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Liu J, Xia L, Xu Z, Wu W, Gao X, Lin L. Applying lysozyme, alkaline protease, and sodium hypochlorite to reduce bioclogging during managed aquifer recharge: A laboratory study. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2023; 332:117371. [PMID: 36739770 DOI: 10.1016/j.jenvman.2023.117371] [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: 10/18/2022] [Revised: 01/08/2023] [Accepted: 01/23/2023] [Indexed: 06/18/2023]
Abstract
Alleviating bacterial-induced clogging is of great importance to improve the efficiency of managed aquifer recharge (MAR). Enzymes (lysozyme and alkaline protease) and sodium hypochlorite (NaClO) are common biological and chemical reagents for inhibiting bacterial growth and activity. To investigate the applicability of these reagents to reduce bioclogging, percolation experiments were performed to simulate a weak alkaline recharge water infiltration through laboratory-scale sand columns, with adding 10 mg/L lysozyme, alkaline protease, and NaClO, respectively. The results showed that, with the addition of lysozyme, alkaline protease, and NaClO, the average clogging rates (the reduced percentages of relative saturated hydraulic conductivity of the sand columns per hour during the percolation experiments) were 0.53%/h, 0.32%/h and 0.06%/h, respectively, which were much lower than that in the control group (0.99%/h). This implied that bioclogging could be alleviated to some extent following the treatments. For further analyzing the mechanisms of the regents on alleviating bioclogging, the bacterial cell amount and extracellular polymeric substances (EPS) concentration were also measured to study the effects of lysozyme, alkaline protease, and NaClO on bacterial growth and EPS secretion. Lysozyme and alkaline protease could disintegrate bacterial EPS by hydrolyzing polysaccharides and proteins, respectively, while they had little effect on the bacterial cell amount. The addition of NaClO significantly decreased the bacterial cell amount (P < 0.05) and thus greatly alleviated bioclogging. Although the lowest average clogging rate was achieved in the NaClO group, it can generate disinfection by-products that are potentially harmful to the environment and human health. Therefore, the biological-based method, i.e., enzyme treatment, could be a promising option for bioclogging control. Our results provide insights for understanding the mechanisms of lysozyme, alkaline protease, and NaClO to alleviate bioclogging, which is of great importance for addressing the clogging problem during MAR activities and achieving groundwater resources sustainable utilization.
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Affiliation(s)
- Jinhui Liu
- College of Earth Science and Engineering, Shandong University of Science and Technology, Qingdao, 266590, China
| | - Lu Xia
- College of Earth Science and Engineering, Shandong University of Science and Technology, Qingdao, 266590, China.
| | - Zilin Xu
- College of Earth Science and Engineering, Shandong University of Science and Technology, Qingdao, 266590, China
| | - Wenli Wu
- College of Earth Science and Engineering, Shandong University of Science and Technology, Qingdao, 266590, China
| | - Xiaobing Gao
- College of Earth Science and Engineering, Shandong University of Science and Technology, Qingdao, 266590, China
| | - Lei Lin
- College of Ocean Science and Engineering, Shandong University of Science and Technology, Qingdao, 266590, China
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Dai Z, Liu L, Duan H, Li B, Tang X, Wu X, Liu G, Zhang L. Improving sludge dewaterability by free nitrous acid and lysozyme pretreatment: Performances and mechanisms. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 855:158648. [PMID: 36096212 DOI: 10.1016/j.scitotenv.2022.158648] [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: 07/26/2022] [Revised: 09/05/2022] [Accepted: 09/06/2022] [Indexed: 06/15/2023]
Abstract
Reducing the water content of waste activated sludge (WAS) is critical for sludge treatment and disposal in wastewater treatment plants (WWTPs). In this study, a new combined conditioning processes by using lysozyme (LZM) and free nitrous acid (FNA) were proposed and demonstrated to enhance the dewaterability of WAS. The water content of sludge cake dropped from 82.82 % to 68.42 % (1 h FNA treatment + 1 h LZM treatment) and 69.52 % (6 h FNA treatment + 1 h LZM treatment) with the combined FNA and LZM treatment; and the corresponding capillary suction time (CST) reduction efficiency increased 49.29 % (1 h FNA treatment + 1 h LZM treatment) and 52.98 % (6 h FNA treatment + 1 h LZM treatment). A comprehensive investigation conducted in this study revealed the underlying mechanism of dewaterability improvement lies in the transformations of extracellular polymeric substances (EPS). The combined conditioning led to enhanced hydrophobicity in the sludge, as suggested by FTIR protein secondary structure and interfacial free energy. The reduced zeta potential and the potential barrier indicated the reduction of the repulsive force of sludge particles and the bound water content in the conditioned floc. The hydrophobicity, flow permeability and flocculability were enhanced after combined treatment, leading to the release of bound water.
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Affiliation(s)
- Ziheng Dai
- School of Environment, Guangdong Provincial Key Laboratory of Chemical Pollution and Environmental Safety, MOE Key Laboratory of Theoretical Chemistry of Environment, Guangdong Provincial Engineering Technology Research Center for Wastewater Management and Treatment, South China Normal University, Guangzhou 510006, China
| | - Lei Liu
- School of Environment and Civil Engineering, Dongguan University of Technology, Dongguan 523808, China.
| | - Haoran Duan
- Australian Centre for Water and Environmental Biotechnology (ACWEB), The University of Queensland, St. Lucia, QLD 4072, Australia
| | - Biqing Li
- Guangzhou sewage purification Co. Ltd., Guangzhou 510655, China
| | - Xia Tang
- Guangzhou sewage purification Co. Ltd., Guangzhou 510655, China
| | - Xuewei Wu
- Guangzhou sewage purification Co. Ltd., Guangzhou 510655, China
| | - Gang Liu
- School of Environment, Guangdong Provincial Key Laboratory of Chemical Pollution and Environmental Safety, MOE Key Laboratory of Theoretical Chemistry of Environment, Guangdong Provincial Engineering Technology Research Center for Wastewater Management and Treatment, South China Normal University, Guangzhou 510006, China
| | - Liguo Zhang
- School of Environment, Guangdong Provincial Key Laboratory of Chemical Pollution and Environmental Safety, MOE Key Laboratory of Theoretical Chemistry of Environment, Guangdong Provincial Engineering Technology Research Center for Wastewater Management and Treatment, South China Normal University, Guangzhou 510006, China.
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15
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Zhang X, Zhang H, Wang Z, Liu T, Guo D, Hu Z. Enhanced paper sludge dewatering and in-depth mechanism by oxalic acid/Fe 2+/persulfate process. CHEMOSPHERE 2023; 311:136966. [PMID: 36280120 DOI: 10.1016/j.chemosphere.2022.136966] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/24/2022] [Revised: 10/17/2022] [Accepted: 10/18/2022] [Indexed: 06/16/2023]
Abstract
As a typical advanced oxidation process, Fe2+-persulfate (PDS) oxidation technology has been widely and efficiently reported for enhancing sludge dewaterability. However, higher dosage of Fe2+ must be added, which will restrain the oxidation efficiency of Fe2+-PDS process. In this work, the oxalic acid (OA)/Fe2+-PDS process was studied to improve paper sludge dewatering. With the OA dosage of 6 μmol (g total solid (TS))-1, Fe2+ dosage of 0.3 mmol (g TS)-1, and PDS dosage of 0.6 mmol (g TS)-1, sludge dewaterability was improved more efficiently. The specific resistance to filtration and water content of sludge cake were decreased by 70.7% and 8.0%, respectively. In comparison with Fe2+-PDS process, the viscosities of sludge suspension and supernatant were further reduced by 3.73% and 51.77%, respectively, and the contents of extracellular polymeric substances fractions were increased. The improved sludge dewaterability in OA/Fe2+-PDS process was mainly contributed by the synergistic effect of oxidative disintegration by free radicals and flocs re-flocculation, the contributions of which were the orders: metal cations > sulfate radical > hydroxyl radical. OA enhanced the efficient disintegration of sludge flocs, released more bound water, generated more Fe3+-oxalate complexes, and finally increased the sludge particle size significantly, forming a larger aggregation and obvious cracks. Additionally, the stabilization of several heavy metals was improved due to the chelating capacity of OA. These works will provide a novel approach for sludge dewatering in the PDS oxidation process.
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Affiliation(s)
- Xin Zhang
- School of Environmental and Natural Resources, Zhejiang University of Science and Technology, Hangzhou, Zhejiang, 310023, China; State Key Laboratory of Pulp and Paper Engineering, South China University of Technology, Guangzhou, Guangdong, 510000, China; Zhejiang Shanying Paper CO., LTD, Jiaxing, Zhejiang, 314000, China; Northeast Petroleum University, Daqing, Heilongjiang, 163318, China.
| | - Hongtao Zhang
- School of Environmental and Natural Resources, Zhejiang University of Science and Technology, Hangzhou, Zhejiang, 310023, China
| | - Zhenchang Wang
- School of Environmental and Natural Resources, Zhejiang University of Science and Technology, Hangzhou, Zhejiang, 310023, China
| | - Tao Liu
- Zhejiang Shanying Paper CO., LTD, Jiaxing, Zhejiang, 314000, China
| | - Daliang Guo
- School of Environmental and Natural Resources, Zhejiang University of Science and Technology, Hangzhou, Zhejiang, 310023, China
| | - Zhijun Hu
- School of Environmental and Natural Resources, Zhejiang University of Science and Technology, Hangzhou, Zhejiang, 310023, China
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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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Li L, Peng C, Zhan Z, Ma F, Zhang J. A novel treatment for amelioration of sludge dewaterability using green starch-grafted flocculant and realized mechanism. Sep Purif Technol 2022. [DOI: 10.1016/j.seppur.2022.122060] [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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18
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Sun M, Xiao K, Zhu Y, Ou B, Yu W, Liang S, Hou H, Yuan S, Gan F, Mi R, Yang J. Deciphering the role of microplastic size on anaerobic sludge digestion: Changes of dissolved organic matter, leaching compounds and microbial community. ENVIRONMENTAL RESEARCH 2022; 214:114032. [PMID: 35952741 DOI: 10.1016/j.envres.2022.114032] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/25/2022] [Revised: 07/24/2022] [Accepted: 07/31/2022] [Indexed: 06/15/2023]
Abstract
Here the role of microplastic size on dissolved organic matter, leaching compounds and microbial community during anaerobic sludge digestion was evaluated. Compared to that without the addition of polyvinyl chloride (PVC), during the 30 days' incubation, the anaerobic sludge digestion by adding PVC at the size of 75 μm and the concentration of 2.4 g/g volatile solids (VS) showed a 8.5% lower cumulative methane production, while a 17.9% higher cumulative methane production was noted by adding PVC at the size of 3000 μm and the concentration of 2.4 g/g VS. A long-term fed-batch laboratory-scale fermenter test for 147 days further testified, that higher removal efficiencies of total solids, volatile solids, and total chemical oxygen demand, and higher methane production were noted by adding PVC (2.4 g/g VS, 3000 μm) into the fermenter. More interestingly, higher concentrations of proteins, polysaccharides, volatile fatty acids, and soluble microbial by-products component were noted in the liquid phase of sludge drawn from the fermenter added with PVC since the biomass therein showed higher efficiencies of solubilization, hydrolysis, acidification, and methanogenesis. Moreover, as identified from the fermenter added with PVC, dibutyl phthalate (DBP) was the most predominant leaching phthalates compound, although the biomass therein showed a 93.4% anaerobic biodegradability of DBP. The leaching of DBP drove the predominance of microbial community towards Synergistota and Methanosaeta. More irregular elliptical shallow dimples were noted on the PVC surface after 147 days' incubation, accompanied with abundances of Proteobacteria, Actinobacteriota, Chloroflexi, Methanosaeta and Methanobacterium. The results from this study showed that the size of microplastic was a crucial factor in evaluating its impact on anaerobic sludge digestion.
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Affiliation(s)
- Mei Sun
- School of Environmental Science and Engineering, Huazhong University of Science and Technology, 1037 Luoyu Road, Wuhan, Hubei, 430074, China
| | - Keke Xiao
- School of Environmental Science and Engineering, Huazhong University of Science and Technology, 1037 Luoyu Road, Wuhan, Hubei, 430074, China.
| | - Yuwei Zhu
- School of Environmental Science and Engineering, Huazhong University of Science and Technology, 1037 Luoyu Road, Wuhan, Hubei, 430074, China
| | - Bei Ou
- School of Environmental Science and Engineering, Huazhong University of Science and Technology, 1037 Luoyu Road, Wuhan, Hubei, 430074, China
| | - Wenbo Yu
- School of Environmental Science and Engineering, Huazhong University of Science and Technology, 1037 Luoyu Road, Wuhan, Hubei, 430074, China
| | - Sha Liang
- School of Environmental Science and Engineering, Huazhong University of Science and Technology, 1037 Luoyu Road, Wuhan, Hubei, 430074, China
| | - Huijie Hou
- School of Environmental Science and Engineering, Huazhong University of Science and Technology, 1037 Luoyu Road, Wuhan, Hubei, 430074, China
| | - Shushan Yuan
- School of Environmental Science and Engineering, Huazhong University of Science and Technology, 1037 Luoyu Road, Wuhan, Hubei, 430074, China
| | - Fangmao Gan
- Yangtze Ecology and Environment Co. Ltd., 96 Xudong Street, Wuhan, Hubei, 430074, China
| | - Rongxi Mi
- Yangtze Ecology and Environment Co. Ltd., 96 Xudong Street, Wuhan, Hubei, 430074, China
| | - Jiakuan Yang
- School of Environmental Science and Engineering, Huazhong University of Science and Technology, 1037 Luoyu Road, Wuhan, Hubei, 430074, China
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19
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Huang X, Yao K, Yu J, Dong W, Zhao Z. Nitrogen removal performance and microbial characteristics during simultaneous chemical phosphorus removal process using Fe 3. BIORESOURCE TECHNOLOGY 2022; 363:127972. [PMID: 36122847 DOI: 10.1016/j.biortech.2022.127972] [Citation(s) in RCA: 18] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/06/2022] [Revised: 09/09/2022] [Accepted: 09/10/2022] [Indexed: 06/15/2023]
Abstract
To evaluate the effect of Fe3+ on nitrogen (N) removal and associated microbial characteristics during simultaneous chemical phosphorus (P) removal, a sequencing batch reactor was used to analyze the changes in the microbial community and metabolic pathways caused by Fe3+ addition. Results demonstrated that Fe3+ promoted ammonia nitrogen (NH4+-N) removal and inhibited denitrification process, and increased the sludge particles (D50) and the biomass per sludge particle size. Furthermore, the abundances of denitrifying bacteria (Haliangium and Terrimonas) and biological phosphorus removing bacteria (Halaingium, norank_f_Saprospiraceae and SM1A02) were decreased. On the contrary, the increase of nitrifying bacteria abundance and the coding genes of nitrification-related enzymes confirmed the promotion for nitrification with Fe3+ addition. Besides, Fe3+ inhibited the interspecific relationship between denitrifying bacteria genera and other genera to reduce denitrification efficiency.
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Affiliation(s)
- Xiao Huang
- Collaborative Innovation Center of Atmospheric Environment and Equipment Technology, Jiangsu Key Laboratory of Atmospheric Environment Monitoring and Pollution Control, School of Environmental Science and Engineering, Nanjing University of Information Science & Technology, Nanjing 210044, China; Shenzhen Key Laboratory of Water Resources Utilization and Environmental Pollution Control, School of Civil and Environmental Engineering, Harbin Institute of Technology (Shenzhen), Shenzhen 518055, China
| | - Kai Yao
- Collaborative Innovation Center of Atmospheric Environment and Equipment Technology, Jiangsu Key Laboratory of Atmospheric Environment Monitoring and Pollution Control, School of Environmental Science and Engineering, Nanjing University of Information Science & Technology, Nanjing 210044, China
| | - Jianghua Yu
- Collaborative Innovation Center of Atmospheric Environment and Equipment Technology, Jiangsu Key Laboratory of Atmospheric Environment Monitoring and Pollution Control, School of Environmental Science and Engineering, Nanjing University of Information Science & Technology, Nanjing 210044, China
| | - Wenyi Dong
- Shenzhen Key Laboratory of Water Resources Utilization and Environmental Pollution Control, School of Civil and Environmental Engineering, Harbin Institute of Technology (Shenzhen), Shenzhen 518055, China
| | - Zilong Zhao
- Shenzhen Key Laboratory of Water Resources Utilization and Environmental Pollution Control, School of Civil and Environmental Engineering, Harbin Institute of Technology (Shenzhen), Shenzhen 518055, China.
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20
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Wang R, Zhu W, Zhao S, Cao J. Hydrothermal oxidation-precipitation method for recovering phosphorus from dewatered sludge and the mechanisms involved. Sep Purif Technol 2022. [DOI: 10.1016/j.seppur.2022.121580] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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21
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Yuan L, Liu H, Lu Y, Lu Y, Wang D. Enhancing the dewaterability of waste activated sludge by the combined ascorbic acid and zero-valent iron/persulfate system. CHEMOSPHERE 2022; 303:135104. [PMID: 35623430 DOI: 10.1016/j.chemosphere.2022.135104] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/22/2022] [Revised: 04/15/2022] [Accepted: 05/22/2022] [Indexed: 06/15/2023]
Abstract
In this work, a reducing/chelating agent, ascorbic acid (H2A) was introduced to the traditional zero-valent iron (Fe0)/persulfate (PS) process for waste activated sludge dewatering. The experimental data indicated that H2A-Fe0/PS process significantly enhanced the dewatering performance of sludge and enhanced the oxidation efficiency of Fe0-PS treatment. Under optimal conditions, the capillary suction time ratio before and after treatment (CST0/CST) of H2A-Fe0/PS treated sludge increased by 118% and 31.3% compared with untreated sludge and Fe0-PS treated sludge, respectively. The mechanism investigations revealed that the H2A-Fe0/PS induced excellent enhancement for sludge dewaterability could be credited to the reduction and chelating capacity of ascorbic acid. Free radicals including SO4•-, O2•- and •OH produced in the H2A-Fe0/PS process destroyed proteinaceous components and humic substances in sludge extracellular polymeric substances (EPS), thus reducing the negative charge and water holding capacity of sludge, improving the sludge rheological properties. As a result, the dewatering performance of sludge has been significantly improved.
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Affiliation(s)
- Longhu Yuan
- State Key Laboratory of Hydrology, Water Resources and Hydraulic Engineering, Nanjing Hydraulic Research Institute, Nanjing, 210029, China.
| | - Huaixiang Liu
- State Key Laboratory of Hydrology, Water Resources and Hydraulic Engineering, Nanjing Hydraulic Research Institute, Nanjing, 210029, China.
| | - Yongjun Lu
- State Key Laboratory of Hydrology, Water Resources and Hydraulic Engineering, Nanjing Hydraulic Research Institute, Nanjing, 210029, China.
| | - Yan Lu
- State Key Laboratory of Hydrology, Water Resources and Hydraulic Engineering, Nanjing Hydraulic Research Institute, Nanjing, 210029, China
| | - Dongbo Wang
- College of Environmental Science and Engineering, Hunan University, Changsha, 410082, PR China; Key Laboratory of Environment Biology and Pollution Control, Hunan University, Ministry of Education, Changsha, 410082, PR China
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22
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Li H, Chen J, Zhang J, Dai T, Yi H, Chen F, Zhou M, Hou H. Multiple environmental risk assessments of heavy metals and optimization of sludge dewatering: Red mud-reed straw biochar combined with Fe 2+ activated H 2O 2. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2022; 316:115210. [PMID: 35550958 DOI: 10.1016/j.jenvman.2022.115210] [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: 01/13/2022] [Revised: 04/22/2022] [Accepted: 04/30/2022] [Indexed: 06/15/2023]
Abstract
In this study, Fe-rich biochar (RMRS-BC) was prepared from red mud and reed straw to improve sludge dewatering and transformation of heavy metals (HMs, including Cd, Cr, Cu, Pb, and Zn). The optimal concentrations of RMRS-BC, Fe2+, and H2O2 to promote sludge dewaterability were identified by response surface methodology (RSM). The optimal dosages of RMRS-BC, Fe2+, and H2O2 were 74.0, 104.9, and 75.7 mg/g dry solids (DS), respectively. The corresponding capillary suction time (CST) and water content of sludge cake were 14.3 s and 51.25 wt%. For the improvement mechanism, heterogeneous and homogeneous Fenton reactions occurred due to RMRS-BC and Fe2+ activating H2O2. The extracellular polymeric substances (EPS) decomposed into dissolved organic matter (proteins and polysaccharides), thereby promoting the transformation of bound water to free water and further reducing the water content of the sludge cake. The research quantitatively assessed the environmental risk of heavy metals in the conditioned sludge cake based on bioavailability and ecotoxicity, pollution levels and potential ecological risks. Compound conditioning using RMRS-BC, Fe2+, and H2O2 could significantly improve the solubility and reduce the leaching toxicity of HMs. In general, RMRS-BC combined with Fe2+ to activate H2O2 provided an effective method to enhance sludge dewaterability and reduce HMs risk.
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Affiliation(s)
- He Li
- School of Resource and Environmental Science, Wuhan University, Wuhan, 430072, Hubei, China
| | - Jiaao Chen
- School of Resource and Environmental Science, Wuhan University, Wuhan, 430072, Hubei, China
| | - Jiaxing Zhang
- School of Resource and Environmental Science, Wuhan University, Wuhan, 430072, Hubei, China
| | - Tenglong Dai
- School of Resource and Environmental Science, Wuhan University, Wuhan, 430072, Hubei, China
| | - Han Yi
- School of Resource and Environmental Science, Wuhan University, Wuhan, 430072, Hubei, China; College of Resources and Environment, Anqing Normal University, Anqing, 246011, Anhui, China
| | - Fangyuan Chen
- School of Resource and Environmental Science, Wuhan University, Wuhan, 430072, Hubei, China
| | - Min Zhou
- School of Resource and Environmental Science, Wuhan University, Wuhan, 430072, Hubei, China
| | - Haobo Hou
- School of Resource and Environmental Science, Wuhan University, Wuhan, 430072, Hubei, China.
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23
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Zhang X, Zhang H, Liu T, Yang J, Wang Z, Chen P. Insights into the respective role of oxidation and flocculation conditioning for enhancing paper sludge dewaterability. Chem Eng Res Des 2022. [DOI: 10.1016/j.cherd.2022.06.011] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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24
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Wu B, Wang H, He Y, Dai X, Chai X. Influential mechanism of water occurrence states of waste-activated sludge: Over-focused significance of cell lysis to bound water reduction. WATER RESEARCH 2022; 221:118737. [PMID: 35716414 DOI: 10.1016/j.watres.2022.118737] [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: 03/01/2022] [Revised: 05/25/2022] [Accepted: 06/09/2022] [Indexed: 06/15/2023]
Abstract
The rigid cell membrane structure is widely thought to retain the intracellular water and positively contributes to the presence of bound water in waste-activated sludge (WAS), which is the main obstacle of its highly-efficient dewatering. However, few studies realized the quantification of intracellular water fraction in the total bound water. Thus, there still may be some debates on whether and what extent of cell lysis is optimal for the dewaterability improvement. This study specifically focused on the effect of microbial cell lysis on the water occurrence states of WAS. The sonication, cyclic freezing-thawing and dimethyl sulfoxide (DMSO) amendment were used as the non-chemical means for cell lysis without altering the chemical compositions of WAS. The extent of cell lysis was quantified by the aqueous lactate dehydrogenase (LDH) released from intracellular cytoplasm and the water occurrence states of WAS were characterized by the transverse relaxation time (T2) spectra of low-field nuclear magnetic resonance (NMR). The results indicated that 8 h sonication (60 W/g dry matter, solid content of WAS: 23.10±0.30 g/L) completely lysed the microbial cells, but only increased the moderately mobile water fraction from 0.555% to 2.370%; similarly, it could be estimated that nearly 15% of cells were destructed after 5 times of freezing-thawing, but the fraction of moderately mobile water only rose from 0.555% to 0.805%. The transmission electron microscope (TEM) with ultrathin sections visually tracked the WAS micro-morphology accompanied with the cell lysis; the sonication caused the notable lysis of microbial cells and dispersed the external encapsulating components, which originally surrounded microbial cells closely; most of the microbial cells could be deformed but wasn't lysed by cyclic freezing-thawing; DMSO amendment made the outer edge of microbial cells tend to be rough, which may reflect the DMSO-enhanced permeability of cell membrane. The correlative analysis further indicated that the capillary suction time (CST) had the close correlation with particle size/zeta potential (Pearson coefficient>0.85, p-value<0.05), but no strong correlation was identified between CST and slightly reduced bound water contents (Pearson coefficient<0.9, p-value≥0.05). Instead of the cell integrity, the compositional aggregation states dominated the water occurrence states of WAS. Highly-efficient conditioning approaches should rely on the reduction of bio-floc porosity through eliminating solid-liquid interfacial affinity instead of damaging the cell membrane structure.
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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
| | - Hao Wang
- State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, 1239 Siping Road, Shanghai 200092, China; Shanghai Municipal Engineering Design Institute (Group) Co., Ltd, 901 Zhongshan North 2nd Road, Shanghai 200092, China
| | - Yunbin He
- Shenzhen Tagen (Group) Co., Ltd, Shenzhen 518034, 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.
| | - 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.
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25
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Liang J, Zhou Y. Iron-based advanced oxidation processes for enhancing sludge dewaterability: State of the art, challenges, and sludge reuse. WATER RESEARCH 2022; 218:118499. [PMID: 35537253 DOI: 10.1016/j.watres.2022.118499] [Citation(s) in RCA: 33] [Impact Index Per Article: 16.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/04/2022] [Revised: 04/12/2022] [Accepted: 04/21/2022] [Indexed: 06/14/2023]
Abstract
The increasing amount of sewage sludge produced in wastewater treatment plants (WWTPs) poses a great challenge to both environment and economy globally. As a requisite process during sludge treatment, sludge dewatering can significantly minimize the sludge volume and lower the operational cost for downstream transportation and disposal. Iron-based advanced oxidation process (AOP), a robust and cost-effective technique with relatively low technical barriers for high-level sludge dewatering, has been widely explored in the past 20 years. The development was mainly driven by the demands of efficient and sustainable sludge conditioning technology and the flexible sludge management approaches. The application of iron-based AOPs in sludge dewatering process attracts more and more attention. In this work, we discussed the current application of iron-based AOPs technology in the sludge dewatering processes in a holistic manner, summarized the factors affecting the sludge dewaterability in the treatment processes, and analyzed the mechanisms of iron-based AOPs to improve dewatering processes. Furthermore, we elaborated potential advantages, limitations, and challenges associated with implementing iron-based AOPs in the full-scale plants and shared the opportunities for sludge reutilization. This review aims to contribute to the development of highly efficient iron-based AOPs for sludge dewatering and offer perspectives and directions towards the new-generation of WWTPs with the sustainable and eco-friendly benefits.
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Affiliation(s)
- Jialin Liang
- Engineering and Technology Research Center for Agricultural Land Pollution Integrated Prevention and Control of Guangdong Higher Education Institute, College of Resources and Environment, Zhongkai University of Agriculture and Engineering, Guangzhou, 510225, China
| | - Yan Zhou
- Advanced Environmental Biotechnology Centre, Nanyang Environment and Water Research Institute, Nanyang Technological University, 637141, Singapore; School of Civil and Environmental Engineering, Nanyang Technological University, 639798, Singapore.
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26
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Li C, Maqbool T, Kang H, Zhang Z. In-Situ Sludge Reduction in Membrane-Controlled Anoxic-Oxic-Anoxic Bioreactor: Performance and Mechanism. MEMBRANES 2022; 12:membranes12070659. [PMID: 35877863 PMCID: PMC9321052 DOI: 10.3390/membranes12070659] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/02/2022] [Revised: 06/20/2022] [Accepted: 06/23/2022] [Indexed: 01/27/2023]
Abstract
Conventional and advanced biological wastewater treatment systems generate excess sludge, which causes socio-economic and environmental issues. This study investigated the performance of membrane-controlled anoxic-oxic-anoxic (AOA) bioreactors for in-situ sludge reduction compared to the conventional anoxic-oxic-oxic membrane bioreactor (MBRcontrol). The membrane units in the AOA bioreactors were operated as anoxic reactors at lower sludge recirculation rates to achieve hydrolysis of extracellular polymeric substances (EPS) and extensive endogenous respiration. Compared to MBRcontrol, the AOA bioreactors operated with 90%, and 80% recirculation rates reduced the sludge growth up to 19% and 30%, respectively. Protein-like components were enriched in AOA bioreactors while fulvic-like components were dominant in MBRcontrol. The growth of Dechloromonas and Zoogloea genra was promoted in AOA bioreactors and thus sludge reduction was facilitated. Metagenomics analysis uncovered that AOA bioreactors exhibited higher proportions of key genes encoding enzymes involved in the glycolysis and denitrification processes, which contributed to the utilization of carbon sources and nitrogen consumption and thus sludge reduction.
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Affiliation(s)
- Chengyue Li
- Institute of Environmental Engineering & Nano-Technology, Tsinghua Shenzhen International Graduate School, Tsinghua University, Shenzhen 518055, China; (C.L.); (T.M.); (H.K.)
- Guangdong Provincial Engineering Research Centre for Urban Water Recycling and Environmental Safety, Tsinghua Shenzhen International Graduate School, Tsinghua University, Shenzhen 518055, China
- School of Environment, Tsinghua University, Beijing 100084, China
| | - Tahir Maqbool
- Institute of Environmental Engineering & Nano-Technology, Tsinghua Shenzhen International Graduate School, Tsinghua University, Shenzhen 518055, China; (C.L.); (T.M.); (H.K.)
- Guangdong Provincial Engineering Research Centre for Urban Water Recycling and Environmental Safety, Tsinghua Shenzhen International Graduate School, Tsinghua University, Shenzhen 518055, China
- School of Environment, Tsinghua University, Beijing 100084, China
| | - Hongyu Kang
- Institute of Environmental Engineering & Nano-Technology, Tsinghua Shenzhen International Graduate School, Tsinghua University, Shenzhen 518055, China; (C.L.); (T.M.); (H.K.)
- Guangdong Provincial Engineering Research Centre for Urban Water Recycling and Environmental Safety, Tsinghua Shenzhen International Graduate School, Tsinghua University, Shenzhen 518055, China
- School of Environment, Tsinghua University, Beijing 100084, China
| | - Zhenghua Zhang
- Institute of Environmental Engineering & Nano-Technology, Tsinghua Shenzhen International Graduate School, Tsinghua University, Shenzhen 518055, China; (C.L.); (T.M.); (H.K.)
- Guangdong Provincial Engineering Research Centre for Urban Water Recycling and Environmental Safety, Tsinghua Shenzhen International Graduate School, Tsinghua University, Shenzhen 518055, China
- School of Environment, Tsinghua University, Beijing 100084, China
- Correspondence:
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27
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Chen R, Dai X, Dong B. Decrease the effective temperature of hydrothermal treatment for sewage sludge deep dewatering: Mechanistic of tannic acid aided. WATER RESEARCH 2022; 217:118450. [PMID: 35452974 DOI: 10.1016/j.watres.2022.118450] [Citation(s) in RCA: 24] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/06/2022] [Revised: 03/15/2022] [Accepted: 04/09/2022] [Indexed: 06/14/2023]
Abstract
The formation of refractory compounds and high nitrogen concentrations in filtrates is the bottleneck of hydrothermal treatment (HT) for sludge deep dewatering. To simultaneously solve these two problems, tannic acid (TA)-aided HT was firstly developed in this study. TA addition improved dewaterability under all investigated HT temperatures by improving the sludge relative hydrophobicity. Moreover, the effective HT temperature was reduced from 180 to 160 ℃. The soluble extracellular polymeric substances (S-EPSs) of the sludge hydrothermally treated at 160 ℃ under the optimal TA dose (0.15 mmol/g total solids) contained 47.27% less total organic nitrogen than the S-EPSs of the raw sludge. This result means that the corresponding filtrate contained lower concentrations of refractory compounds and nitrogen than those under the conventional HT conditions and thus could be more easily treated. Furthermore, the changes in the protein secondary structure and the interaction of TA with high-molecular-weight (HMW) proteins in S-EPSs were found to be highly relevant (p < 0.05) to the improvement of sludge dewaterability. With increasing HT temperature (120-180 ℃), the S-EPS HMW proteins with numerous hydrophilic functional groups (hydroxyl and carboxyl) were hydrolyzed, and their secondary structures unfolded; consequently, more sites were exposed for hydrophobic binding with TA, and the TA-protein interaction was more stable and spontaneous. The precipitation of protein with TA also increased with the HT temperature. Thus, TA-aided HT improves protein precipitation and sludge dewaterability through protein structure destruction and the production of more hydrophobic binding sites for TA. The identification of the influencing mechanisms on SS EPS-TA interaction mode and binding capacity are conducive to the further upgrading of TA-aided HT for engineering applications.
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Affiliation(s)
- Renjie Chen
- School of Environmental Science and Engineering, Tongji University, Shanghai 200092, PR China
| | - Xiaohu Dai
- School of Environmental Science and Engineering, Tongji University, Shanghai 200092, PR China; Shanghai Institute of Pollution Control and Ecological Security, Shanghai 200092, PR China
| | - Bin Dong
- School of Environmental Science and Engineering, Tongji University, Shanghai 200092, PR China; Shanghai Institute of Pollution Control and Ecological Security, Shanghai 200092, PR China; YANGTZE Eco-Environment Engineering Research Center, China Three Gorges Corporation, Beijing 100038, PR China.
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28
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Tian L, Guo H, Wang Y, Su Z, Zhu T, Liu Y. Insights into Fe(Ⅱ)-sulfite-based pretreatment strategy for enhancing short-chain fatty acids (SCFAs) production from waste activated sludge: Performance and mechanism. BIORESOURCE TECHNOLOGY 2022; 353:127143. [PMID: 35427734 DOI: 10.1016/j.biortech.2022.127143] [Citation(s) in RCA: 23] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/13/2022] [Revised: 04/06/2022] [Accepted: 04/07/2022] [Indexed: 05/21/2023]
Abstract
This paper proposed a concept of "co-treating" waste activated sludge (WAS) with waste-derived sulfite and environmentally-friendly ferrous iron. The maximal short-chain fatty acids (SCFAs) production from WAS anaerobic fermentation ascended by 27.1 times after pretreated by Fe(Ⅱ) activated sulfite with a sulfite dosage of 500 mg S/L and a Fe(Ⅱ)/sulfite ratio of 1.25. Mechanism explorations elucidated that the production of SO4·- and ·OH induced by Fe(Ⅱ)-activated sulfite-auto-oxidation remarkably promoted the disintegration of WAS and the biodegradability of dissolved organic matter, leading to enrichment of substances available for SCFAs-producing microbes. Besides, activities of hydrolytic and acidogenic enzymes were stimulated, while enzymes related to SCFAs consumption were inhibited severely. Further microbial community investigation confirmed that the abundances of hydrolytic microorganisms and acidogens were enriched. In addition, sludge dewaterability and vivianite production was enhanced after Fe(Ⅱ)-sulfite pretreated WAS fermentation, thereby benefiting the subsequent sludge disposal and resource recovery.
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Affiliation(s)
- Lixin Tian
- School of Environmental Science and Engineering, Tianjin University, Tianjin 300072, PR China
| | - Haixiao Guo
- School of Environmental Science and Engineering, Tianjin University, Tianjin 300072, PR China
| | - Yufen Wang
- School of Environmental Science and Engineering, Tianjin University, Tianjin 300072, PR China
| | - Zhongxian Su
- School of Environmental Science and Engineering, Tianjin University, Tianjin 300072, PR China
| | - Tingting Zhu
- School of Environmental Science and Engineering, Tianjin University, Tianjin 300072, PR China
| | - Yiwen Liu
- School of Environmental Science and Engineering, Tianjin University, Tianjin 300072, PR China.
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29
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Reinterpretation of the mechanism of coagulation and its effects in waste activated sludge treatment. Sep Purif Technol 2022. [DOI: 10.1016/j.seppur.2022.120958] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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30
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Ding A, Lin W, Chen R, Ngo HH, Zhang R, He X, Nan J, Li G, Ma J. Improvement of sludge dewaterability by energy uncoupling combined with chemical re-flocculation: Reconstruction of floc, distribution of extracellular polymeric substances, and structure change of proteins. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 816:151646. [PMID: 34774632 DOI: 10.1016/j.scitotenv.2021.151646] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/25/2021] [Revised: 10/26/2021] [Accepted: 11/09/2021] [Indexed: 06/13/2023]
Abstract
This study innovatively combines energy uncoupling and chemical re-flocculation helped to accelerate residual sludge dewatering. Ferric chloride (FeCl3) and 3, 3', 4', 5-tetrachlor-osalicylanilide (TCS) were employed as the flocculant and uncoupler, respectively. The results showed that the specific resistance to filtration (SRF) and the water content of sludge filtered cake fell dramatically from 11 × 1012 m/kg and 80.2% to 1.1 × 1012 m/kg and 77.1% respectively, when the addition of TCS ranged from 0 to 0.12 g/g VSS with flocculation conditioning. The distribution of sludge extracellular polymeric substance (EPS) was altered radically after adding TCS, leading to the collapse and fragmentation of EPS, causing the reduction and formation of fragmentized sludge flocs. Meanwhile, the stretching and deformation vibrations of CO and NH bonds suggested the strong attack between TCS and EPS proteins, while variations of the main secondary structures of protein (i.e. α-helix, β-sheet and random coil) indicated the loose structure of proteins and enhanced hydrophobicity. Consequently, the cracked and loose structure of residual sludge resulted in the release of bound water. After TCS addition combined with chemical re-flocculation, the channels of sludge water discharge were widened, guaranteeing the discharge of sludge water. Therefore, the sludge dewaterability was elevated under the energy uncoupling combined with chemical re-flocculation. As well, the application of TCS would not destroy sludge cells, in which bioenergy (sludge carbon source) could be retained and effectively utilized in the subsequent disposal process. The findings reported here not only widen our perception of the energy uncoupling technology, but also encourage researchers to explore both effective and economic methods on the basis of energy uncoupling, aiming to achieve high-efficiency of reduction and dewatering in the future.
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Affiliation(s)
- 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, PR China.
| | - 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, PR 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, PR China
| | - Huu Hao Ngo
- Faculty of Engineering, University of Technology Sydney, P.O. Box 123, Broadway, Sydney, NSW 2007, Australia
| | - Rourou Zhang
- State Key Laboratory of Urban Water Resource and Environment (SKLUWRE), School of Environment, Harbin Institute of Technology, 73 Huanghe Road, Nangang District, 150090 Harbin, PR China
| | - 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, PR 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, PR 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, PR 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, PR China
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31
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Wang J, Li M, Guan A, Liu R, Qi W, Liu H, Qu J. Can radicals-orientated chemical oxidation improve the reduction of antibiotic resistance genes (ARGs) by mesophilic anaerobic digestion of sludge? JOURNAL OF HAZARDOUS MATERIALS 2022; 426:128001. [PMID: 34933261 DOI: 10.1016/j.jhazmat.2021.128001] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/11/2021] [Revised: 11/19/2021] [Accepted: 12/04/2021] [Indexed: 06/14/2023]
Abstract
The dissemination of antibiotic resistance genes (ARGs) increases risks towards human health and environmental safety. This work investigates the control of ARGs abundance and bacterial community evolution involved in waste activated sludge (WAS) treatment by chemical conditioning and subsequent mesophilic anaerobic digestion (MAD). The different chemical oxidation processes of ferrous iron-activated oxone and hydrogen peroxide (PMS-Fe2+ and H2O2-Fe2+) and thermal-activated oxone (PMS@80 ℃) were investigated, and the ferric chloride (FeCl3) and inactivated oxone (PMS) were compared. PMS@80 ℃ decreased the absolute abundance of most ARGs by 10.6-99.3% and that of total ARGs by 66.3%. Interestingly, oxidation pretreatment increased rather than decreased the relative abundance of most ARGs. MAD with PMS@80 ℃ pretreatment increased the absolute abundance of total ARGs by 51.6%, and other MAD processes decreased it by 8.6-47.4%. PMS-Fe2+ and PMS@80 ℃ negatively inhibited methane production from 98.3 to 81.7 and 94.4 mL/g VSS in MAD. MAD effluent showed high abundance of Arcobacter genus in the range of 8.1-17.4% upon PMS-based pretreatment, possibly related to sulfur oxidation, nitrate reduction, and blaVEB enrichment. The radicals-orientated chemical oxidation can hardly improve the ARGs elimination by MAD due to the extremely high competitive organics in sludge.
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Affiliation(s)
- Jiaqi Wang
- Key Laboratory of Drinking Water Science and Technology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Mengtian Li
- Key Laboratory of Drinking Water Science and Technology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Aomei Guan
- Key Laboratory of Drinking Water Science and Technology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Ruiping Liu
- Center for Water and Ecology, State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing 100084, China
| | - Weixiao Qi
- Center for Water and Ecology, State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing 100084, China.
| | - Huijuan Liu
- Center for Water and Ecology, State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing 100084, China
| | - Jiuhui Qu
- Key Laboratory of Drinking Water Science and Technology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; University of Chinese Academy of Sciences, Beijing 100049, China; Center for Water and Ecology, State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing 100084, China
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Li L, Peng C, Deng L, Zhang F, Wu D, Ma F, Liu Y. Understanding the synergistic mechanism of PAM-FeCl 3 for improved sludge dewaterability. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2022; 301:113926. [PMID: 34731962 DOI: 10.1016/j.jenvman.2021.113926] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/14/2020] [Revised: 09/26/2021] [Accepted: 10/07/2021] [Indexed: 06/13/2023]
Abstract
Hybrid flocculant polyacrylamide-ferric chloride (PAM-FeCl3) was developed to improve the dewaterability of sewage sludge and the dewatering performance, properties of treated sludge, composition and morphology distribution of extracellular polymeric substance (EPS) were investigated. The physicochemical properties of the PAM-FeCl3 were characterized, and its effectiveness as a sludge conditioner was evaluated. The results indicated that PAM-FeCl3 conditioning was able to promote sludge dewaterability. Simultaneously, PAM-FeCl3 neutralized the negative charges on the surface of sludge particles and increased the sludge floc size. Besides, PAM-FeCl3 also formed a rough and porous floc structure that reduced sludge compressibility. Meanwhile, the exciting emission matrix analysis suggested that PAM-FeCl3 can effectively disintegrate of EPS fraction in sludge and decompose the aromatic protein-like substances as well as the humic acid-like substances in EPS. Additionally, the larger sludge floc formation, electrostatic interaction and adsorption bridging effect resulted in compression of sludge structure and the decomposition of EPS fractions and improved sludge dewatering performance.
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Affiliation(s)
- Lixin Li
- School of Environmental and Chemical Engineering, Heilongjiang University of Science and Technology, Harbin, 150022, China; Longjiang Environmental Protection Group Co. Ltd, Harbin, 150050, China; State Key Lab of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin, 150001, China.
| | - Cheng Peng
- School of Environmental and Chemical Engineering, Heilongjiang University of Science and Technology, Harbin, 150022, China
| | - Lihua Deng
- School of Environmental and Chemical Engineering, Heilongjiang University of Science and Technology, Harbin, 150022, China
| | - Fugui Zhang
- Longjiang Environmental Protection Group Co. Ltd, Harbin, 150050, China.
| | - Dan Wu
- Longjiang Environmental Protection Group Co. Ltd, Harbin, 150050, China
| | - Fang Ma
- State Key Lab of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin, 150001, China
| | - Yan Liu
- College of Life Science and Technology, Harbin Normal University, Harbin, 150020, China
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Guo H, Wang Y, Tian L, Wei W, Zhu T, Liu Y. Insight into the enhancing short-chain fatty acids (SCFAs) production from waste activated sludge via polyoxometalates pretreatment: Mechanisms and implications. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 800:149392. [PMID: 34388643 DOI: 10.1016/j.scitotenv.2021.149392] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/20/2021] [Revised: 07/25/2021] [Accepted: 07/28/2021] [Indexed: 05/21/2023]
Abstract
Polyoxometalates (POMs), a versatile and environmentally-friendly inorganic material, have been extensively studied and applied in chemical catalytic oxidation and biological nutrients removal processes. However, little is known about effects of POMs pretreatment on anaerobic sludge fermentation. This study thereby filled such knowledge gap and provided insights into the underlying mechanisms. Results demonstrated the maximal short-chain fatty acids (SCFAs) production increased by 6.18 times with POMs rising from 0 to 0.05 g/g TSS. Mechanistic investigations revealed that the oxidation stress of POMs as well as reactive oxygen species (ROS) activated by POMs were responsible for the disintegration of waste activated sludge (WAS). More importantly, POMs pretreatment improved the biodegradability of organics released, providing more biodegradable substrates for SCFAs generation. Furthermore, the inhibition of POMs to SCFAs producers was less severe than that to SCFAs consumers, leading to SCFAs accumulation. Microbial community analysis exhibited that increased the population of hydrolysis (i.e., Longilinea) and SCFAs generation microbes (i.e., Acinetobacter and Fusibacter). Further evaluation showed that the POMs-based technology is economically and environmentally attractive for the pretreatment of WAS. Finally, a "closed-loop" concept of the reutilization of renewable POMs may provide an important implication of WAS management in the future.
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Affiliation(s)
- Haixiao Guo
- School of Environmental Science and Engineering, Tianjin University, Tianjin 300072, PR China
| | - Yufen Wang
- School of Environmental Science and Engineering, Tianjin University, Tianjin 300072, PR China
| | - Lixin Tian
- School of Environmental Science and Engineering, Tianjin University, Tianjin 300072, PR China
| | - Wei Wei
- School of Environment, Harbin Institute of Technology, Harbin 150090, P. R. China
| | - Tingting Zhu
- School of Environmental Science and Engineering, Tianjin University, Tianjin 300072, PR China
| | - Yiwen Liu
- School of Environmental Science and Engineering, Tianjin University, Tianjin 300072, PR China.
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Xiao K, Li N, Yang C, Zhu Y, Yu Z, Yu W, Liang S, Hou H, Liu B, Hu J, Yang J. Deciphering the impacts of composition of extracellular polymeric substances on sludge dewaterability: An often overlooked role of amino acids. CHEMOSPHERE 2021; 284:131297. [PMID: 34182288 DOI: 10.1016/j.chemosphere.2021.131297] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/07/2021] [Revised: 05/20/2021] [Accepted: 06/17/2021] [Indexed: 06/13/2023]
Abstract
An investigation was conducted for waste activated sludge pretreated by different methods (e.g., ultrasonic, thermal, ozone, and acid/alkaline) in order to establish correlations between amino acids and parameters related to sludge dewaterability (e.g., capillary suction time (CST), specific resistance to filtration (SRF), proteins (PN) and polysaccharides (PS) in different fractions of extracellular polymeric substances (EPS), zeta potential, and particle sizes). The results indicated that glycine, serine, and threonine were the key identified amino acids correlated with parameters related to sludge dewaterability. To be exemplified, glycine showed positive correlations with the normalized CST (regression coefficient (R) = 0.72, p < 0.05), the normalized SRF (R = 0.74, p < 0.05), PN in soluble EPS (R = 0.89, p < 0.05), PS in soluble EPS (R = 0.56, p < 0.05), tryptophan-like PN in soluble EPS (R = 0.60, p < 0.05), and tryptophan-like PN in loosely-bound EPS (R = 0.58, p < 0.05). After adding extra glycine, serine, and threonine into sludge samples, sludge dewaterability was deteriorated. The hydrophilic functional groups of CO and C-OH were found to be more predominant in sludge with the presence of these amino acids. The Lewis acid-base interaction predominated in determining the net attraction among sludge flocs. Moreover, the presence of glycine, serine, and threonine resulted in high repulsive hydrophilic interaction, which deteriorated sludge dewaterability. This study emphasized the importance of amino acids in sludge dewatering and amino acids might be incorporated into parameters reflecting sludge dewaterability.
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Affiliation(s)
- Keke Xiao
- School of Environmental Science and Engineering, Huazhong University of Science and Technology, Luoyu Road 1037, Wuhan, Hubei, 430074, China; Hubei Provincial Engineering Laboratory of Solid Waste Treatment, Disposal and Recycling, Luoyu Road 1037, Wuhan, Hubei, 430074, China
| | - Na Li
- School of Environmental Science and Engineering, Huazhong University of Science and Technology, Luoyu Road 1037, Wuhan, Hubei, 430074, China; Hubei Provincial Engineering Laboratory of Solid Waste Treatment, Disposal and Recycling, Luoyu Road 1037, Wuhan, Hubei, 430074, China
| | - Changzhu Yang
- School of Environmental Science and Engineering, Huazhong University of Science and Technology, Luoyu Road 1037, Wuhan, Hubei, 430074, China; Hubei Provincial Engineering Laboratory of Solid Waste Treatment, Disposal and Recycling, Luoyu Road 1037, Wuhan, Hubei, 430074, China.
| | - Yuwei Zhu
- School of Environmental Science and Engineering, Huazhong University of Science and Technology, Luoyu Road 1037, Wuhan, Hubei, 430074, China; Hubei Provincial Engineering Laboratory of Solid Waste Treatment, Disposal and Recycling, Luoyu Road 1037, Wuhan, Hubei, 430074, China
| | - Zecong Yu
- School of Environmental Science and Engineering, Huazhong University of Science and Technology, Luoyu Road 1037, Wuhan, Hubei, 430074, China; Hubei Provincial Engineering Laboratory of Solid Waste Treatment, Disposal and Recycling, Luoyu Road 1037, Wuhan, Hubei, 430074, China
| | - Wenbo Yu
- School of Environmental Science and Engineering, Huazhong University of Science and Technology, Luoyu Road 1037, Wuhan, Hubei, 430074, China; Hubei Provincial Engineering Laboratory of Solid Waste Treatment, Disposal and Recycling, Luoyu Road 1037, Wuhan, Hubei, 430074, China
| | - Sha Liang
- School of Environmental Science and Engineering, Huazhong University of Science and Technology, Luoyu Road 1037, Wuhan, Hubei, 430074, China; Hubei Provincial Engineering Laboratory of Solid Waste Treatment, Disposal and Recycling, Luoyu Road 1037, Wuhan, Hubei, 430074, China
| | - Huijie Hou
- School of Environmental Science and Engineering, Huazhong University of Science and Technology, Luoyu Road 1037, Wuhan, Hubei, 430074, China; Hubei Provincial Engineering Laboratory of Solid Waste Treatment, Disposal and Recycling, Luoyu Road 1037, Wuhan, Hubei, 430074, China.
| | - Bingchuan Liu
- School of Environmental Science and Engineering, Huazhong University of Science and Technology, Luoyu Road 1037, Wuhan, Hubei, 430074, China; Hubei Provincial Engineering Laboratory of Solid Waste Treatment, Disposal and Recycling, Luoyu Road 1037, Wuhan, Hubei, 430074, China
| | - Jingping Hu
- School of Environmental Science and Engineering, Huazhong University of Science and Technology, Luoyu Road 1037, Wuhan, Hubei, 430074, China; Hubei Provincial Engineering Laboratory of Solid Waste Treatment, Disposal and Recycling, Luoyu Road 1037, Wuhan, Hubei, 430074, China
| | - Jiakuan Yang
- School of Environmental Science and Engineering, Huazhong University of Science and Technology, Luoyu Road 1037, Wuhan, Hubei, 430074, China; Hubei Provincial Engineering Laboratory of Solid Waste Treatment, Disposal and Recycling, Luoyu Road 1037, Wuhan, Hubei, 430074, China; State Key Laboratory of Coal Combustion, Huazhong University of Science and Technology, Luoyu Road 1037, Wuhan, Hubei, 430074, China; Hubei Water Quality Safety and Water Pollution Control Engineering Center, Luoyu Road 1037, Wuhan, Hubei, 430074, China.
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Zhang R, Lu X, Tan Y, Cai T, Han Y, Kudisi D, Niu C, Zhang Z, Li W, Zhen G. Disordered mesoporous carbon activated peroxydisulfate pretreatment facilitates disintegration of extracellular polymeric substances and anaerobic bioconversion of waste activated sludge. BIORESOURCE TECHNOLOGY 2021; 339:125547. [PMID: 34315087 DOI: 10.1016/j.biortech.2021.125547] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/04/2021] [Revised: 07/07/2021] [Accepted: 07/09/2021] [Indexed: 05/21/2023]
Abstract
The potential of disordered mesoporous carbon (DMC) as catalyst of peroxydisulfate (PDS) to improve sludge solubilization and methane production was investigated. Results showed that DMC activated PDS (DMC/PDS) to produce sulfate radicals (SO4-), facilitating cells rupture and sludge matrix dissociation by degrading the carbonyl and amide groups in organic biopolymers (especially proteins, polysaccharides and humus). At the optimal DMC/PDS dosage of 0.04/1.2 g-mmol/g-VS, SCOD was increased from initial 294.0 to 681.5 mg/L, with the methane production rate of 12.6 mL/g-VS/day. Moreover, DMC could serve as electron mediator to accelerate electron transfer of microorganisms, building a more robust anaerobic metabolic environment. Modelling analysis further demonstrated the crucial role of DMC/PDS pretreatment in biological degradation and methane productivity. This study indicated that DMC/PDS pretreatment can prominently enhance the release of soluble substances and methane production, aiding the utilization of PDS oxidation technology for improving anaerobic bioconversion of sludge.
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Affiliation(s)
- Ruiliang Zhang
- Shanghai Key Lab for Urban Ecological Processes and Eco-Restoration, School of Ecological and Environmental Sciences, East China Normal University, Shanghai 200241, PR China
| | - Xueqin Lu
- Shanghai Key Lab for Urban Ecological Processes and Eco-Restoration, School of Ecological and Environmental Sciences, East China Normal University, Shanghai 200241, PR China; Institute of Eco-Chongming (IEC), 3663 N Zhongshan Rd, Shanghai 200062, PR China; Shanghai Engineering Research Center of Biotransformation of Organic Solid Waste, Shanghai 200241, PR China.
| | - Yujie Tan
- Shanghai Key Lab for Urban Ecological Processes and Eco-Restoration, School of Ecological and Environmental Sciences, East China Normal University, Shanghai 200241, PR China
| | - Teng Cai
- Shanghai Key Lab for Urban Ecological Processes and Eco-Restoration, School of Ecological and Environmental Sciences, East China Normal University, Shanghai 200241, PR China
| | - Yule Han
- Shanghai Key Lab for Urban Ecological Processes and Eco-Restoration, School of Ecological and Environmental Sciences, East China Normal University, Shanghai 200241, PR China
| | - Dilibaierkezi Kudisi
- Shanghai Key Lab for Urban Ecological Processes and Eco-Restoration, School of Ecological and Environmental Sciences, East China Normal University, Shanghai 200241, PR China
| | - Chengxin Niu
- Shanghai Key Lab for Urban Ecological Processes and Eco-Restoration, School of Ecological and Environmental Sciences, East China Normal University, Shanghai 200241, PR China
| | - Zhongyi Zhang
- Shanghai Key Lab for Urban Ecological Processes and Eco-Restoration, School of Ecological and Environmental Sciences, East China Normal University, Shanghai 200241, PR China
| | - Wanjiang Li
- Shanghai Key Lab for Urban Ecological Processes and Eco-Restoration, School of Ecological and Environmental Sciences, East China Normal University, Shanghai 200241, PR China
| | - Guangyin Zhen
- Shanghai Key Lab for Urban Ecological Processes and Eco-Restoration, School of Ecological and Environmental Sciences, East China Normal University, Shanghai 200241, PR China; Shanghai Engineering Research Center of Biotransformation of Organic Solid Waste, Shanghai 200241, PR China; Shanghai Institute of Pollution Control and Ecological Security, 1515 North Zhongshan Rd. (No. 2), Shanghai 200092, PR China; Technology Innovation Center for Land Spatial Eco-restoration in Metropolitan Area, Ministry of Natural Resources, 3663 N Zhongshan Road, Shanghai 200062, PR China
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Wang Z, Liu T, Duan H, Song Y, Lu X, Hu S, Yuan Z, Batstone D, Zheng M. Post-treatment options for anaerobically digested sludge: Current status and future prospect. WATER RESEARCH 2021; 205:117665. [PMID: 34547700 DOI: 10.1016/j.watres.2021.117665] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/30/2021] [Revised: 08/15/2021] [Accepted: 09/10/2021] [Indexed: 05/16/2023]
Abstract
Anaerobic digestion is the most commonly used sludge treatment technology in large-scale wastewater treatment plants (WWTPs), generating two main products, i.e., biogas and anaerobically digested (AD) sludge. Biogas can be used as a source of renewable energy, and AD sludge is often transported for agricultural land application. Land application of AD sludge is confronted with ever-increasing economic and regulatory pressures due to its high water content, high organic content and related odour and pathogen content (if poorly stabilized), as well as potential toxic metal and organic contaminants. To address these challenges, a number of technologies have been developed for the further treatment of AD sludge before final disposal. This review aims to critically evaluate these state-of-the-art technologies. These technologies were categorized based on their primary aims: 1) dewaterability enhancement; 2) solids reduction and stabilization; 3) toxic metals removal. At present, the goal of post-treatment mainly focuses on dewaterability enhancement, to reduce transport costs. In future, we propose that the post-treatment of AD sludge should orient towards multiple aims, i.e., an integrated approach enabling sludge volume reduction, stabilization (including pathogen removal), and metal solubilization simultaneously. Two promising technical routes are suggested as examples, i.e. physio-chemical iron-based advanced oxidation and biological acidic aerobic digestion, while more approaches need to be developed in future studies. We concluded that post-treatment of AD sludge will promote the AD sludge management towards a more economically favourable, socially acceptable, and environmentally sustainable way; however, further development and rigorous evaluation are required for a wider adoption.
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Affiliation(s)
- Zhiyao Wang
- Advanced Water Management Centre, The University of Queensland, St Lucia, QLD 4072, Australia
| | - Tao Liu
- Advanced Water Management Centre, The University of Queensland, St Lucia, QLD 4072, Australia
| | - Haoran Duan
- Advanced Water Management Centre, The University of Queensland, St Lucia, QLD 4072, Australia
| | - Yarong Song
- Advanced Water Management Centre, The University of Queensland, St Lucia, QLD 4072, Australia
| | - Xi Lu
- Advanced Water Management Centre, The University of Queensland, St Lucia, QLD 4072, Australia
| | - Shihu Hu
- Advanced Water Management Centre, The University of Queensland, St Lucia, QLD 4072, Australia
| | - Zhiguo Yuan
- Advanced Water Management Centre, The University of Queensland, St Lucia, QLD 4072, Australia
| | - Damien Batstone
- Advanced Water Management Centre, The University of Queensland, St Lucia, QLD 4072, Australia
| | - Min Zheng
- Advanced Water Management Centre, The University of Queensland, St Lucia, QLD 4072, Australia.
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Hu P, Shen S, Zhao D, Wei H, Ge J, Jia F, Zhang X, Yang H. The influence of hydrophobicity on sludge dewatering associated with cationic starch-based flocculants. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2021; 296:113218. [PMID: 34246906 DOI: 10.1016/j.jenvman.2021.113218] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/04/2021] [Revised: 06/25/2021] [Accepted: 07/01/2021] [Indexed: 06/13/2023]
Abstract
Coagulation/flocculation is an extensive and effective pretreatment technology for improving the sludge dewaterability. A series of hydrophobically associated cationic starch-based flocculants (CS-DMRs) with different degrees of hydrophobicity but similar charge densities were designed and synthesized. The CS-DMRs exhibited excellent sludge dewatering performance. The dewaterability of sludge increased with the hydrophobicity of the CS-DMRs, and the filter cake moisture content (FCMC) and specific resistance to filtration (SRF) could be reduced from 95.47% and 7.09 × 1012 m/kg to 79.26% and 2.258 × 1012 m/kg, respectively, at a constant pressure of 0.05 MPa after conditioned by the starch-based flocculant with the highest hydrophobicity at its optimal dose. Moreover, due to their amphiphilic structures, CS-DMRs could closely interact with the negatively charged extracellular polymeric substances (EPS), efficiently compress the protein and polysaccharide in EPS, and release the bound water. A second-order polynomial model was proposed according to the phenomenological theory to quantitatively analyze the effect of hydrophobicity in these starch-based flocculants on the sludge dewaterability. The structure-activity relationship was built, and the optimal dose and corresponding FCMC could be theoretically estimated accordingly. The results were in good agreement with the experimental results. The dewatering mechanisms were also discussed in detail on the basis of the changes in the FCMC, SRF, capillary suction time, properties of sludge flocs, compression coefficient, microstructures of sludge cakes, EPS fractions and components, and spatial distributions of the proteins and polysaccharides. In addition to charge neutralization, the hydrophobic association effects of CS-DMRs played an important role in the formation of drainage channels and net-like porous structures in the sludge cake to improve its permeability and filterability. This study thus provided a good understanding of the structural effects of the starch-based flocculants on the sludge dewaterability. The results are greatly beneficial to the fabrication and utilization of environment-friendly and high-performance natural polymeric conditioners for sludge treatment.
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Affiliation(s)
- Pan Hu
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing, 210023, PR China
| | - Shaohang Shen
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing, 210023, PR China
| | - Donghua Zhao
- Shanghai Waterway Engineering Design and Consulting Co., LTD., Shanghai, 200120, PR China
| | - Hua Wei
- Shanghai Waterway Engineering Design and Consulting Co., LTD., Shanghai, 200120, PR China
| | - Jun Ge
- Shanghai Waterway Engineering Design and Consulting Co., LTD., Shanghai, 200120, PR China
| | - Feiyue Jia
- Shanghai Waterway Engineering Design and Consulting Co., LTD., Shanghai, 200120, PR China
| | - Xiangxiang Zhang
- Shanghai Waterway Engineering Design and Consulting Co., LTD., Shanghai, 200120, PR China
| | - Hu Yang
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing, 210023, PR China; Quanzhou Institute for Environmental Protection Industry, Nanjing University, Beifeng Road, Quanzhou, 362000, PR China.
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Ge D, Zhu Y, Li G, Yuan H, Zhu N. Identifying the key sludge properties characteristics in Fe 2+-activated persulfate conditioning for dewaterability amelioration and engineering implementation. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2021; 296:113204. [PMID: 34243089 DOI: 10.1016/j.jenvman.2021.113204] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/31/2021] [Revised: 06/29/2021] [Accepted: 06/30/2021] [Indexed: 06/13/2023]
Abstract
Fe2+-activated persulfate process has been introduced into sludge conditioning currently, however the key sludge properties characteristics are worthwhile comprehensively considering for the engineering implementation and management. The results indicated that both the optimal dosages of persulfate and Fe2+ were 0.6 mmol/gTS for sludge dewaterability amelioration, and the reduction efficiencies of capillary suction time (CST), specific resistance of filtration (SRF), and water content (Wc) of dewatered sludge cake reached to 90.5%, 97.2%, and 22.4%, respectively. Significantly, the persulfate and Fe2+ exerted distinctive roles in the conditioning process. The increased persulfate could promote the oxidatively disintegrated effect on sludge flocs, rendering the decrease of particle size. With the oxidative decomposition of the negatively charged biopolymers, sludge zeta potential rose gradually. However, Fe2+ contributed to more persulfate activation to generate free radicals, and the produced Fe3+ could further electrically neutralize the broken sludge fragments. The core mechanism of Fe2+-activated persulfate conditioning is "destroying and re-building" of sludge flocs. Noteworthily, EPS protein was oxidatively degraded more preferentially than EPS polysaccharide, and the decrease of the α-helix content of EPS protein was conducive to the enhancement of sludge dewaterability. Furthermore, the hydrophilic functional groups reduced clearly and element chemical states on sludge flocs altered pronouncedly, also the destroyed structure and microchannel facilitated the flowability of water. These findings provide theoretical and technical support for the practical engineering implementation of the Fe2+-activated persulfate conditioning process.
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Affiliation(s)
- Dongdong Ge
- School of Environmental Science & Engineering, Shanghai Jiao Tong University, Shanghai, 200240, China
| | - Yidan Zhu
- Jinhua Academy of Agricultural Sciences, Jinhua, Zhejiang, 321025, China
| | - Guobiao Li
- School of Environmental Science & Engineering, Shanghai Jiao Tong University, Shanghai, 200240, China
| | - Haiping Yuan
- School of Environmental Science & Engineering, Shanghai Jiao Tong University, Shanghai, 200240, China
| | - Nanwen Zhu
- School of Environmental Science & Engineering, Shanghai Jiao Tong University, Shanghai, 200240, China; Shanghai Institute of Pollution Control and Ecological Security, Shanghai, 200092, China.
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Li Y, Wang D, Yang G, Yuan X, Yuan L, Li Z, Xu Q, Liu X, Yang Q, Tang W, Jiang L, Li H, Wang Q, Ni B. In-depth research on percarbonate expediting zero-valent iron corrosion for conditioning anaerobically digested sludge. JOURNAL OF HAZARDOUS MATERIALS 2021; 419:126389. [PMID: 34323710 DOI: 10.1016/j.jhazmat.2021.126389] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/01/2021] [Revised: 06/08/2021] [Accepted: 06/08/2021] [Indexed: 06/13/2023]
Abstract
Anaerobically digested sludge (ADS) is commonly hard to dewater for the presence of extracellular polymeric substances (EPS) and the liberation of glutinous soluble microbic products during anaerobic digestion. Sodium percarbonate (SPC) expediting zero-valent iron (ZVI) corrosion (SPC/ZVI) process firstly conditioned ADS to amend its dewaterability. Results showed that SPC/ZVI conditioning decreased moisture content of dewatered cake from 90.5% (control) to 69.9% with addition of 0.10 g/g TS SPC and 0.20 g/g TS ZVI. Mechanistic research indicated that the enhanced ADS dewaterability mainly resulted from •OH and Fe(III)/iron polymers yielded in SPC/ZVI. •OH disrupted EPS, damaged cytoderm & cytomembrane, and lysed intracellular substances, unbinding the bound water. Meanwhile, the breakage and inactivation of microbe by •OH prompted the production of macro-pores in ADS. •OH adjusted the conformation of extracellular/intracellular proteins by intervening in the H-bonds and S-S bonds, availing the hydrophobicity and slight flocculation of ADS. •OH further facilitated the despiralization of α-helical to β-sheet structure in ADS pellets, benefiting cell-to-cell aggregation. Additionally, Fe(III)/iron polymers from ZVI corrosion accelerated to gather ADS and maintained its floc structure. Consequently, SPC/ZVI conditioning not only adjusted the natures of ADS and its EPS but also the features of residual pellets, which further induced the advancement of ADS dewaterability. In addition, SPC/ZVI conditioning possibly surmounts some limitations existing in ZVI/Peroxide or ZVI/Persulfate technique.
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Affiliation(s)
- Yifu Li
- College of Environmental Science and Engineering, Hunan University, Changsha 410082, PR China; Key Laboratory of Environment Biology and Pollution Control, Hunan University, Ministry of Education, Changsha 410082, PR China.
| | - Dongbo Wang
- College of Environmental Science and Engineering, Hunan University, Changsha 410082, PR China; Key Laboratory of Environment Biology and Pollution Control, Hunan University, Ministry of Education, Changsha 410082, PR China.
| | - Guojing Yang
- College of Biological and Environmental Sciences, Zhejiang Wanli University, Ningbo 315100, PR China.
| | - Xingzhong Yuan
- College of Environmental Science and Engineering, Hunan University, Changsha 410082, PR China; Key Laboratory of Environment Biology and Pollution Control, Hunan University, Ministry of Education, Changsha 410082, PR China
| | - Longhu Yuan
- College of Environmental Science and Engineering, Hunan University, Changsha 410082, PR China; Key Laboratory of Environment Biology and Pollution Control, Hunan University, Ministry of Education, Changsha 410082, PR China
| | - Zijing Li
- College of Environmental Science and Engineering, Hunan University, Changsha 410082, PR China; Key Laboratory of Environment Biology and Pollution Control, Hunan University, Ministry of Education, Changsha 410082, PR China
| | - Qiuxiang Xu
- College of Environmental Science and Engineering, Hunan University, Changsha 410082, PR China; Key Laboratory of Environment Biology and Pollution Control, Hunan University, Ministry of Education, Changsha 410082, PR China
| | - Xuran Liu
- College of Environmental Science and Engineering, Hunan University, Changsha 410082, PR China; Key Laboratory of Environment Biology and Pollution Control, Hunan University, Ministry of Education, Changsha 410082, PR China
| | - Qi Yang
- College of Environmental Science and Engineering, Hunan University, Changsha 410082, PR China; Key Laboratory of Environment Biology and Pollution Control, Hunan University, Ministry of Education, Changsha 410082, PR China
| | - Wangwang Tang
- College of Environmental Science and Engineering, Hunan University, Changsha 410082, PR China; Key Laboratory of Environment Biology and Pollution Control, Hunan University, Ministry of Education, Changsha 410082, PR China
| | - Longbo Jiang
- College of Environmental Science and Engineering, Hunan University, Changsha 410082, PR China; Key Laboratory of Environment Biology and Pollution Control, Hunan University, Ministry of Education, Changsha 410082, PR China
| | - Hailong Li
- School of Energy Science and Engineering, Central South University, Changsha 410083, PR China
| | - Qilin Wang
- Centre for Technology in Water and Wastewater, School of Civil and Environmental Engineering, University of Technology Sydney, Sydney, NSW 2007, Australia
| | - Bingjie Ni
- Centre for Technology in Water and Wastewater, School of Civil and Environmental Engineering, University of Technology Sydney, Sydney, NSW 2007, Australia
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Liang J, Liao X, Ye M, Guan Z, Mo Z, Yang X, Huang S, Sun S. Dewaterability improvement and environmental risk mitigation of waste activated sludge using peroxymonosulfate activated by zero-valent metals: Fe 0 vs. Al 0. CHEMOSPHERE 2021; 280:130686. [PMID: 33957470 DOI: 10.1016/j.chemosphere.2021.130686] [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: 01/08/2021] [Revised: 04/10/2021] [Accepted: 04/22/2021] [Indexed: 06/12/2023]
Abstract
The stabilization and dewaterability of waste activated sludge (WAS) are essential factors for downstream disposal or reuse. Herein, two types of zero-valent metals, zero-valent iron (Fe0) and zero-valent aluminum (Al0), were compared for their ability to activate peroxymonosulfate (PMS) during the WAS conditioning process, with the effects of PMS activation by these two metals on WAS dewaterability and the potential environmental risks evaluated. Results showed that compared to Al0/PMS treatment, Fe0/PMS treatment achieved superior WAS dewaterability and reduced operational costs. Using PMS combined with Fe0 and Al0 treatments under optimal conditions, the water content (Wc) of dewatered sludge decreased to 55.7 ± 2.7 wt% and 59.4 ± 1.3 wt%, respectively. Meanwhile, application of the Fe0/PMS treatment system reduced the total annual cost by approximately 33.1%, compared to the Al0/PMS treatment. Analysis of the dewatering mechanism demonstrated that in the Fe0/PMS treatment, Fe3+/Fe2+ flocculation played an important role in the enhancement of WAS dewatering, while sulfate radical (SO4•-) oxidation was the dominant factor for WAS dewaterability improvement in Al0/PMS treatment. The greater enhancement of WAS dewaterability by Fe0/PMS treatment, was mainly attributed to more efficient reduction of hydrophilic extracellular polymeric substances (EPS) and an increase in surface charge neutralization. Environmental risk evaluation results indicated that Fe0/PMS and Al0/PMS treatments both effectively alleviated the environmental risks of heavy metals and faecal coliforms in dewatered sludge. Overall, this study proposes a novel perspective for the selection of an optimal PMS activator in sludge treatment.
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Affiliation(s)
- Jialin Liang
- Guangzhou Key Laboratory Environmental Catalysis and Pollution Control, Guangdong Key Laboratory of Environmental Catalysis and Health Risk Control, School of Environmental Science and Engineering, Institute of Environmental Health and Pollution Control, Guangdong University of Technology, Guangzhou, 510006, China; Institute of Bioresource and Agriculture, Department of Biology, Hong Kong Baptist University, Hong Kong
| | - Xiaojian Liao
- Guangzhou Key Laboratory Environmental Catalysis and Pollution Control, Guangdong Key Laboratory of Environmental Catalysis and Health Risk Control, School of Environmental Science and Engineering, Institute of Environmental Health and Pollution Control, Guangdong University of Technology, Guangzhou, 510006, China
| | - Maoyou Ye
- College of Resources and Environment, Zhongkai University of Agriculture and Engineering, Guangzhou, 510225, China
| | - Zhijie Guan
- Guangzhou Key Laboratory Environmental Catalysis and Pollution Control, Guangdong Key Laboratory of Environmental Catalysis and Health Risk Control, School of Environmental Science and Engineering, Institute of Environmental Health and Pollution Control, Guangdong University of Technology, Guangzhou, 510006, China
| | - Zhihua Mo
- Guangzhou Key Laboratory Environmental Catalysis and Pollution Control, Guangdong Key Laboratory of Environmental Catalysis and Health Risk Control, School of Environmental Science and Engineering, Institute of Environmental Health and Pollution Control, Guangdong University of Technology, Guangzhou, 510006, China
| | - Xian Yang
- Guangzhou Key Laboratory Environmental Catalysis and Pollution Control, Guangdong Key Laboratory of Environmental Catalysis and Health Risk Control, School of Environmental Science and Engineering, Institute of Environmental Health and Pollution Control, Guangdong University of Technology, Guangzhou, 510006, China
| | - Shaosong Huang
- Guangzhou Key Laboratory Environmental Catalysis and Pollution Control, Guangdong Key Laboratory of Environmental Catalysis and Health Risk Control, School of Environmental Science and Engineering, Institute of Environmental Health and Pollution Control, Guangdong University of Technology, Guangzhou, 510006, China.
| | - Shuiyu Sun
- Guangzhou Key Laboratory Environmental Catalysis and Pollution Control, Guangdong Key Laboratory of Environmental Catalysis and Health Risk Control, School of Environmental Science and Engineering, Institute of Environmental Health and Pollution Control, Guangdong University of Technology, Guangzhou, 510006, China; Guangdong Polytechnic of Environmental Protection Engineering, Foshan, 528216, China.
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Arshad Z, Maqbool T, Shin KH, Kim SH, Hur J. Using stable isotope probing and fluorescence spectroscopy to examine the roles of substrate and soluble microbial products in extracellular polymeric substance formation in activated sludge process. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 788:147875. [PMID: 34134356 DOI: 10.1016/j.scitotenv.2021.147875] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/28/2021] [Revised: 05/14/2021] [Accepted: 05/14/2021] [Indexed: 06/12/2023]
Abstract
In this study, we used stable isotope-labeled soluble microbial products (SMP) and substrates to explore their assimilation into the formation of new biological products (i.e., extracellular polymeric substances and biomass) in two adjacent sequencing batch reactors. The isotope labeling approach along with fluorescence spectroscopy allowed us to distinguish between refractory and labile portions of SMP constituents as well as their roles in the formation of extracellular polymeric substances (EPS). Comparison of SMP fluorescence and the specific UV absorbance values between the two reactors revealed the presence of humic-like aromatic substances in the non-consumable part of SMP, which can be ultimately released as effluent organic matter. Parallel factor analysis modeling of fluorescence spectra showed that the hydrolysis of EPS contents mostly resulted in humic-like components in SMP rather than protein-like components, which were initially abundant in EPS (>80%). From variations in carbon and nitrogen isotopic contents in EPS and biomass, it was found that carbon-containing substrates were enriched faster than their nitrogenous counterparts. The contributions to new EPS formation reached 87.5% for carbon and 60.5% for nitrogen. Meanwhile, the isotopic tracking of the labeled SMP revealed that only 11.0% and 11.9% of carbon and 13.3% and 11.6% of nitrogen from the influent SMP were finally assimilated into EPS and biomass, respectively. In contrast, the isotopic enrichment in SMP was higher (~50%) than that of EPS and biomass, indicating the low bioavailability and refractory nature of the feed SMP. This study proposed a promising approach for estimating the relative contributions of different forms of labile substrate and SMP to the formation of EPS in activated sludge processes. This approach could be suggested as a versatile method for establishing the kinetics, substrate element flow, mass balance on organic substrates and nutrients, as well as for tracking the consumption and uptake pathways of hazardous materials.
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Affiliation(s)
- Zeshan Arshad
- Department of Environment and Energy, Sejong University, Seoul 05006, South Korea
| | - Tahir Maqbool
- Institute of Environmental Engineering & Nano-Technology, Tsinghua Shenzhen International Graduate School, Tsinghua University, Shenzhen 518055, Guangdong, China
| | - Kyung Hoon Shin
- Department of Environmental Marine Sciences, Hanyang University, Ansan, Gyeonggi do 15588, South Korea
| | - Seung-Hee Kim
- Department of Environmental Marine Sciences, Hanyang University, Ansan, Gyeonggi do 15588, South Korea
| | - Jin Hur
- Department of Environment and Energy, Sejong University, Seoul 05006, South Korea.
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He D, Bao B, Sun M, Chen J, Luo H, Li J. Enhanced dewatering of activated sludge by acid assisted Heat-CaO 2 treatment: Simultaneously removing heavy metals and mitigating antibiotic resistance genes. JOURNAL OF HAZARDOUS MATERIALS 2021; 418:126248. [PMID: 34111741 DOI: 10.1016/j.jhazmat.2021.126248] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/28/2021] [Revised: 04/28/2021] [Accepted: 05/25/2021] [Indexed: 06/12/2023]
Abstract
High water content and accumulation of heavy metals and antibiotic resistance genes (ARGs) in sewage sludge limit its application. Fenton process has been widely used in sludge dewatering, but the use of hydrogen peroxide (H2O2) and generation of acid sludge are the main drawbacks. Here, a novel method of heat-CaO2 treatment was proposed to enhance sludge dewatering. Results showed that CaO2 (12.5 mg/g dry solids (DS)) combined with heat at 60 °C significantly improved the sludge dewaterability, e.g. the water content decreased from 79.9% to 69.2% and the specific resistance to filtration (SRF) decreased from 9.21 × 1013 to 1.51 × 1013 m/kg. At 62.5 mg CaO2/g DS, the final pH of filtrate was close to neutral and the good dewatering performance was still achieved. The improvement of sludge dewaterability was closely correlated with the decomposition of tightly-bound extracellular polymeric substances (EPS), lysis of the sludge cells, and increased particle size of the flocs. The distribution of bacterial community in the sludge has changed, leading to the decreases in the percentage of some ARGs. The concentrations of typical heavy metals wrapped in the sludge colloid network dramatically reduced. Economic analyses showed that the heat-CaO2 treatment was a promising method for sludge disposal.
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Affiliation(s)
- Dongqin He
- Key Laboratory of Microbial Technology for Industrial Pollution Control of Zhejiang Province, College of Environment, Zhejiang University of Technology, Hangzhou 310014, China
| | - Bo Bao
- Key Laboratory of Microbial Technology for Industrial Pollution Control of Zhejiang Province, College of Environment, Zhejiang University of Technology, Hangzhou 310014, China
| | - Mingkai Sun
- Key Laboratory of Microbial Technology for Industrial Pollution Control of Zhejiang Province, College of Environment, Zhejiang University of Technology, Hangzhou 310014, China
| | - Jingyi Chen
- Key Laboratory of Microbial Technology for Industrial Pollution Control of Zhejiang Province, College of Environment, Zhejiang University of Technology, Hangzhou 310014, China
| | - Hongwei Luo
- Key Laboratory of Microbial Technology for Industrial Pollution Control of Zhejiang Province, College of Environment, Zhejiang University of Technology, Hangzhou 310014, China
| | - Jun Li
- Key Laboratory of Microbial Technology for Industrial Pollution Control of Zhejiang Province, College of Environment, Zhejiang University of Technology, Hangzhou 310014, China.
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Wu B, Wang H, Dai X, Chai X. Influential mechanism of water occurrence states of waste-activated sludge: specifically focusing on the roles of EPS micro-spatial distribution and cation-dominated interfacial properties. WATER RESEARCH 2021; 202:117461. [PMID: 34343872 DOI: 10.1016/j.watres.2021.117461] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/24/2021] [Revised: 06/30/2021] [Accepted: 07/21/2021] [Indexed: 06/13/2023]
Abstract
The highly hydrated colloidal structure of waste-activated sludge (WAS) is the main obstacle of enhanced dewatering for sludge volume minimization. Extracellular polymeric substances (EPS) maintain the colloidal stability of bio-flocs in a three-dimensional matrix due to bindings with bivalent cations (i.e., Ca2+ and Mg2+) and hydrophobic interactions. However, few studies specifically focused on the quantitative relationships among spatial distribution of EPS, microstructure of bio-flocs and fractions of bound water (e.g. vicinal water and interstitial water). Thus, there may be still some debates on whether and what extent of the lysis or flocculation of sludge flocs is optimal for the dewaterability improvement. This study applied the gradient addition of cation exchange resin (CER) to remove EPS-complexed cations and loosen the spatial distribution of EPS. Consequently, how the spatial extension of EPS layers with relief of complex cations influenced the particle size distribution, fractal dimension, interfacial free energy and water occurrence states of WAS was systematically investigated. The quartz crystal microbalance with dissipation (QCM-D) was also applied to analyze the water-EPS interactions with and without the presence of Ca2+ and Mg2+. All the results confirmed that the dispersed EPS adhering layers led to the higher fractal dimension (Df) but the lower space filling degree of bio-flocs. Also, the 4-fold reduction in the polar/acid-based interfacial free energy could be induced by the removal of cations from EPS matrix, which indicated the significant increase in hydrophobicity. Predictably, the fractions of vicinal water and interstitial water were dominated by the polar/acid-based interfacial free energy and pore structure of microbial aggregates, respectively, which were confirmed by the strong Pearson correlation (Rp>0.80, p-value<0.04). These findings are expected to provide the improved mechanistic insights into the relationship between water occurrence states and colloidal structure of WAS, and can serve as the basis for the optimal combination of various sludge conditioning approaches towards regulating aggregation states of bio-flocs.
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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
| | - Hao Wang
- State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, 1239 Siping Road, 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.
| | - 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.
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Lan B, Jin R, Liu G, Dong B, Zhou J, Xing D. Improving waste activated sludge dewaterability with sodium periodate pre-oxidation on extracellular polymeric substances. WATER ENVIRONMENT RESEARCH : A RESEARCH PUBLICATION OF THE WATER ENVIRONMENT FEDERATION 2021; 93:1680-1689. [PMID: 33713351 DOI: 10.1002/wer.1553] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/18/2020] [Revised: 03/02/2021] [Accepted: 03/03/2021] [Indexed: 05/21/2023]
Abstract
The efficiency of sludge dewatering is affected by the structure and composition of hydrated extracellular polymeric substances (EPS). Degrading EPS can improve the sludge dewatering performance. As an oxidizing agent, sodium periodate (NaIO4 ) has ability to oxidize organics, which is expected to decompose the protein and polysaccharide in EPS and improve the efficiency of sludge dewaterability. This study adopted NaIO4 , for the first time, as an advanced oxidation agent to regulate EPS of waste activated sludge and was combined with anionic polyacrylamide (APAM) as a flocculant to subsequently enhance sludge dewatering. Response surface methodology (RSM) was used to determine the optimal conditions of pH, NaIO4 , and APAM. The results showed that the composite conditioner's specific resistance of filtration (SRF) and the water content of the vacuum-filtered cake (Wc) were highly enhanced compared with those of the raw sludge (RS) under pH 6.5, a NaIO4 concentration of 50 mg/g dry solids (DS), and an APAM concentration of 5 mg/g DS. Owing to the pre-oxidation achieved by NaIO4 under a mildly acid environment, sludge flocs were broken. Subsequently, chemical coagulation (APAM) agglomerated the smaller particles into larger flocs of sludge by adsorption and bridging, thus improving sludge dewaterability. PRACTITIONER POINTS: A novel conditioner, pH/NaIO4 /APAM, was explored for sludge dewatering. IO3 • and HO• oxidized extracellular polymeric substances (EPS). Degradation of the protein content of EPS released bound water. Highly enhanced sludge dewaterability was achieved under optimal conditions.
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Affiliation(s)
- Bingbing Lan
- Key Laboratory of Industrial Ecology and Environmental Engineering (Ministry of Education, China), School of Environmental Science and Technology, Dalian University of Technology, Dalian, China
| | - Ruofei Jin
- Key Laboratory of Industrial Ecology and Environmental Engineering (Ministry of Education, China), School of Environmental Science and Technology, Dalian University of Technology, Dalian, China
- State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin, China
| | - Guangfei Liu
- Key Laboratory of Industrial Ecology and Environmental Engineering (Ministry of Education, China), School of Environmental Science and Technology, Dalian University of Technology, Dalian, China
| | - Bin Dong
- Key Laboratory of Industrial Ecology and Environmental Engineering (Ministry of Education, China), School of Environmental Science and Technology, Dalian University of Technology, Dalian, China
| | - Jiti Zhou
- Key Laboratory of Industrial Ecology and Environmental Engineering (Ministry of Education, China), School of Environmental Science and Technology, Dalian University of Technology, Dalian, China
| | - Defeng Xing
- State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin, China
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45
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Conditioning of Sewage Sludge with Physical, Chemical and Dual Methods to Improve Sewage Sludge Dewatering. ENERGIES 2021. [DOI: 10.3390/en14165079] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The paper presents the impact of different methods of sewage sludge conditioning on the improvement of sludge dewatering during pressure filtration processes. The following conditioning methods were tested for sludge preparation: sonication, addition of organic and inorganic chemicals (Zetag 8180, PIX 113 and the combined action of both substances). The research covered: physical and chemical analysis of sewage sludge, measurement of capillary suction time as an indicator of sludge dewaterability, some technical parameters of sludge pressure filtration process and the analysis of filtrate to assess the degree of contamination. The results of the research showed that the final water content of the prepared sludge decreased, while the specific filtration resistance increased. Among the tested methods the best results of sludge dewatering effects were obtained for sonicated sludge and its preparation with inorganic coagulant PIX 113. The combined effect of sonication with the addition of chemicals Zetag 8180 and PIX113 to sludge allowed for the reduction of organic substances, ammonium nitrogen and phosphates in filtrate after sludge dewatering.
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Li E, Wang Y, Zhang D, Fan X, Han Z, Yu F. Siderite/PMS conditioning-pressurized vertical electro-osmotic dewatering process for activated sludge volume reduction: Evolution of protein secondary structure and typical amino acid in EPS. WATER RESEARCH 2021; 201:117352. [PMID: 34157572 DOI: 10.1016/j.watres.2021.117352] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/11/2021] [Revised: 05/20/2021] [Accepted: 06/07/2021] [Indexed: 06/13/2023]
Abstract
In this study, the siderite/PMS conditioning-pressurized vertical electro-osmotic dewatering (PEOD) process was used to reduce the volume of activated sludge (AS). The changes in water content, cell, extracellular polymeric substances (EPS) distribution, protein secondary structures and typical amino acids in EPS fractions of AS along siderite/PMS conditioning-PEOD process were investigated. Results showed that the final water content (WC) of dewatered AS was 58.02% under the RSM optimized conditioning conditions of 0.05 g/g TSS siderite dosage, 0.23 g/g TSS PMS dosage, 600 kPa mechanical pressure and 20 V voltage. At conditioning and PEOD stages, the bound water content(BWC) of AS decreased by 25.23% and 91.76%, respectively. The HO• and SO4-· generated from siderite activating PMS could lead to the disruption of cells. The ratio of Ala-to Lys (Ala/Lys) showed strong negative correlations with BWC or WC in slime (RBWC2=-0.803, p<0.01; RWC2=-0.771, p<0.01) and TB-EPS (RBWC2=-0.693, p<0.01; RWC2=-0.705, p<0.01), and could be considered as an indicator of AS dewaterability. Compared with raw AS, conditioning led to the occurrence of the denser protein structure in TB-EPS and the looser one in slime. The contact number between Ala-and water decreased in TB-EPS and increased in slime, which indicated that the migration of water adhered in TB-EPS to outer layer. At the DG, MC and EC process, while the looser protein structure in TB-EPS and the denser one in slime occurred, as well as higher contact number between Ala-and water in TB-EPS than that in slime, which indicated that more water flowed outsider of slime than TB-EPS. This implied that the variations of the compactness of protein secondary structures and the contact number between Ala-and water in EPS layers correlated with AS dewaterability.
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Affiliation(s)
- Enrui Li
- College of Environmental Science and Engineering, Beijing Key Lab for Source Control Technology of Water Pollution, Beijing Forestry University, Beijing 100083, China
| | - Yili Wang
- College of Environmental Science and Engineering, Beijing Key Lab for Source Control Technology of Water Pollution, Beijing Forestry University, Beijing 100083, China.
| | - Daxin Zhang
- College of Environmental Science and Engineering, Beijing Key Lab for Source Control Technology of Water Pollution, Beijing Forestry University, Beijing 100083, China
| | - Xiaoyang Fan
- College of Environmental Science and Engineering, Beijing Key Lab for Source Control Technology of Water Pollution, Beijing Forestry University, Beijing 100083, China
| | - Zhibo Han
- College of Environmental Science and Engineering, Beijing Key Lab for Source Control Technology of Water Pollution, Beijing Forestry University, Beijing 100083, China
| | - Fuling Yu
- College of Science, Beijing Forestry University, Beijing 100083, China
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Liang J, Zhang L, Zhou Y. Pyrite assisted peroxymonosulfate sludge conditioning: Uncover triclosan transformation during treatment. JOURNAL OF HAZARDOUS MATERIALS 2021; 413:125368. [PMID: 33609874 DOI: 10.1016/j.jhazmat.2021.125368] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/30/2020] [Revised: 01/23/2021] [Accepted: 02/07/2021] [Indexed: 06/12/2023]
Abstract
Waste activated sludge (WAS) dewatering is a crucial process for sludge treatment and disposal. In this study, we proposed a novel pyrite (FeS2) and peroxymonosulfate (PMS) treatment to improve WAS dewaterability. Micropollutants are commonly enriched in the sludge. It is not clear if the micropollutants remain in the sludge during the conditioning. Triclosan (TCS) as a widely used bactericide often presents in the WAS, thus was chosen as a target micropollutant. Pyrite + PMS treatment could simultaneously enhance WAS dewaterability and TCS removal with low cost and high benefit. Under the optimal conditions, the specific resistance of filtration (SRF) and capillary suction time (CST) were reduced by 84.60% and 74.91%, respectively. Meanwhile, the TCS removal efficiency was 34.08% with four transformation products identified. During the pyrite + PMS process, sulfate radicals and hydroxyl radicals were generated and strong flocculation was induced by iron. These two processes significantly reduced the sticky biopolymers, hydrophilic functional groups, and hydrophilic protein molecular structure of extracellular polymeric substances (EPS), leading to the release of bound water and TCS. Collectively, the pyrite + PMS treatment is a promising alternative for simultaneous enhancement of WAS dewatering and micropollutants removal, which is beneficial to the downstream treatment.
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Affiliation(s)
- Jialin Liang
- Advanced Environmental Biotechnology Centre, Nanyang Environment and Water Research Institute, Nanyang Technological University, 637141, Singapore; Institute of Bioresource and Agriculture, Department of Biology, Hong Kong Baptist University, Hong Kong, China
| | - Liang Zhang
- Advanced Environmental Biotechnology Centre, Nanyang Environment and Water Research Institute, Nanyang Technological University, 637141, Singapore
| | - Yan Zhou
- Advanced Environmental Biotechnology Centre, Nanyang Environment and Water Research Institute, Nanyang Technological University, 637141, Singapore; School of Civil and Environmental Engineering, Nanyang Technological University, 639798, Singapore.
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Ranjbar F, Karrabi M, Danesh S, Gheibi M. Improvement of wastewater sludge dewatering using ferric chloride, aluminum sulfate, and calcium oxide (experimental investigation and descriptive statistical analysis). WATER ENVIRONMENT RESEARCH : A RESEARCH PUBLICATION OF THE WATER ENVIRONMENT FEDERATION 2021; 93:1138-1149. [PMID: 33522044 DOI: 10.1002/wer.1526] [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: 09/27/2020] [Revised: 01/19/2021] [Accepted: 01/21/2021] [Indexed: 06/12/2023]
Abstract
In this research, application of chemical conditioners for the conditioning of sludge and their effects on the improvement of sludge thickening of the wastewater treatment plant in the city of Bojnourd (Iran) is investigated. The concentration of chemical conditioners, pH and coagulation and flocculation time is from among the parameters studied in this research work. The results obtained indicate that sludge volume reduction for the chemical conditioners used, including Ferric Chloride (FeCl3 ), Aluminum Sulfate (Al2 (SO4 )3 ), and Calcium Oxide (CaO) are 41, 17, and 33 percent, respectively. The optimal concentration for FeCl3 , Al2 (SO4 )3, and CaO are 550, 1100, and 292 mg/L, respectively, and the optimal values of pH are 9, 7.5, and 10, respectively. The time to filtration (TTF) and reduction in sludge moisture content (SMC) for Ferric Chloride, Aluminum Sulfate, and Calcium Oxide are 45 s and 6.2%, 135 s and 3.3%, 190 s and 2.4% respectively. PRACTITIONER POINTS: Investigating the sludge conditioning by Ferric Chloride, Aluminum Sulfate, and Calcium Oxide. Determining the optimal concentration, pH, and coagulation/flocculation time. Calculating the time to filtration (TTF) and reduction in sludge moisture content (SMC). Predicting the settled sludge volume using descriptive statistical analysis.
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Affiliation(s)
- Flora Ranjbar
- Department of Civil Engineering, Faculty of Engineering, Ferdowsi University of Mashhad, Mashhad, Iran
| | - Mohsen Karrabi
- Department of Civil Engineering, Faculty of Engineering, Ferdowsi University of Mashhad, Mashhad, Iran
| | - Shahnaz Danesh
- Department of Civil Engineering, Faculty of Engineering, Ferdowsi University of Mashhad, Mashhad, Iran
| | - Mohammad Gheibi
- Department of Civil Engineering, Faculty of Engineering, Ferdowsi University of Mashhad, Mashhad, Iran
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Ding N, Wang X, Jiang L, Zhang J, Geng Y, Dong L, Liu H. Enhancement of sludge dewaterability by a magnetic field combined with coagulation/flocculation: a comparative study on municipal and citric acid-processing waste-activated sludge. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2021; 28:35728-35737. [PMID: 33675498 DOI: 10.1007/s11356-021-13278-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/14/2020] [Accepted: 03/01/2021] [Indexed: 06/12/2023]
Abstract
The difficulties in dewatering waste-activated sludge (WAS) using mechanical devices have caused great problems in sludge transportation and disposal. Herein, coagulation and flocculation are combined with the use of a magnetic field as a clean and low-energy physical treatment method to enhance the dewaterability of municipal and citric acid-processing WAS. It is shown that the use of the magnetic field had a significant effect on the capillary suction time (CST) of municipal WAS but not on the specific resistance filtration (SRF) and CST of the citric acid WAS. The differences in the magnetic field effects were due to differences in the sludge properties. For municipal WAS, the particle size decreased, the zeta potential remained unchanged, and the viscosity decreased, whereas in the citric acid WAS, the particle size increased, the absolute value of the zeta potential decreased, and the viscosity increased. In addition, these effects were also confirmed with studies of the water state and micro-morphology analyses. It is shown that the acidification of the municipal WAS and coagulation of citric acid WAS were likely the reasons for the enhancement of their dewaterability, respectively. This study confirmed that the use of a magnetic field combined with coagulation/flocculation may serve as an effective sludge conditioning method; however, the treatment conditions may vary with the sludge type.
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Affiliation(s)
- Ning Ding
- State Environmental Protection Key Laboratory of Food Chain Pollution Control, Beijing Technology and Business University, Beijing, China.
- School of Ecology and Environment, Beijing Technology and Business University, Fucheng Road No.11, Haidian District, Beijing, 100048, China.
- Key Laboratory of Cleaner Production and Comprehensive Utilization of Resources, China National Light Industry, Beijing Technology and Business University, Beijing, China.
| | - Xiao Wang
- School of Ecology and Environment, Beijing Technology and Business University, Fucheng Road No.11, Haidian District, Beijing, 100048, China
| | - Lin Jiang
- School of Ecology and Environment, Beijing Technology and Business University, Fucheng Road No.11, Haidian District, Beijing, 100048, China
| | - Jianxin Zhang
- School of Ecology and Environment, Beijing Technology and Business University, Fucheng Road No.11, Haidian District, Beijing, 100048, China
| | - Yue Geng
- School of Ecology and Environment, Beijing Technology and Business University, Fucheng Road No.11, Haidian District, Beijing, 100048, China
| | - Liming Dong
- State Environmental Protection Key Laboratory of Food Chain Pollution Control, Beijing Technology and Business University, Beijing, China
- School of Ecology and Environment, Beijing Technology and Business University, Fucheng Road No.11, Haidian District, Beijing, 100048, China
- Key Laboratory of Cleaner Production and Comprehensive Utilization of Resources, China National Light Industry, Beijing Technology and Business University, Beijing, China
| | - Hong Liu
- School of Environmental Science and Engineering, Suzhou University of Science and Technology, Jiangsu Province, China
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Zhang J, Qi Y, Zhang X, Zhang G, Yang H, Nattabi F. Experimental investigation of sludge dewatering for single- and double-drainage conditions with a vacuum negative pressure load at the bottom. PLoS One 2021; 16:e0253806. [PMID: 34181699 PMCID: PMC8238177 DOI: 10.1371/journal.pone.0253806] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2021] [Accepted: 06/14/2021] [Indexed: 11/18/2022] Open
Abstract
The moisture content of municipal sludge is relatively high, which increases the cost of sludge transportation and treatment. To reduce the volume of the sludge, sludge dewatering is needed. This paper proposes the theory of sludge dewatering and facilitates efficient and economical technology of sludge dewatering. Sludge dewatering tests were carried out by using homemade rapid sludge dewatering devices. There were two groups of tests with single- and double-drainage conditions, and all test runs were loaded with a negative vacuum pressure at the bottom. During the experiments, the vacuum degree and the pore water pressure in the sludge were monitored in real time. After the experiments, the data were compared and analyzed. At the initial stage, the sludge dewatering extent and the sludge dewatering velocity for double-drainage conditions were much higher than those for single-drainage conditions. The vacuum occurring for single-drainage conditions lagged behind that for double-drainage conditions in the sludge. The value of vacuum degree for single-drainage conditions was lower than that for double-drainage conditions, and the vacuum attenuation for single-drainage conditions was considerable. The excess pore water pressure for double-drainage conditions dissipated faster than that for single-drainage conditions in the sludge. The pore water pressure for single-drainage conditions at the top and middle of the sludge layer first increased and then decreased in the early loading stage, resembling the Mandel effect. Overall, with a vacuum negative pressure load at the bottom, the sludge dewatering efficiency for double-drainage conditions was much higher than that for single-drainage conditions. This study provides an experimental and theoretical basis for engineering applications in the sludge treatment industry.
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Affiliation(s)
- Jiesheng Zhang
- The First Engineering Co., LTD. of CTCE Group, Hefei, China
| | - Yongzheng Qi
- School of Civil Engineering and Architecture, Jiangsu University of Science and Technology, Zhenjiang, China
- * E-mail:
| | - Xue Zhang
- School of Civil Engineering and Architecture, Jiangsu University of Science and Technology, Zhenjiang, China
- School of Traffic & Transportation Engineering, Changsha University of Science and Technology, Changsha, China
| | - Guofu Zhang
- School of Civil Engineering and Architecture, Jiangsu University of Science and Technology, Zhenjiang, China
| | - Hang Yang
- School of Civil Engineering and Architecture, Jiangsu University of Science and Technology, Zhenjiang, China
| | - Firdawus Nattabi
- School of Civil Engineering and Architecture, Jiangsu University of Science and Technology, Zhenjiang, China
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