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Qiu L, Yan C, Zhang Y, Chen Y, Nie M. Hypochlorite-mediated degradation and detoxification of sulfathiazole in aqueous solution and soil slurry. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2024; 350:124039. [PMID: 38670426 DOI: 10.1016/j.envpol.2024.124039] [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: 02/20/2024] [Revised: 04/21/2024] [Accepted: 04/22/2024] [Indexed: 04/28/2024]
Abstract
Although various activated sodium hypochlorite (NaClO) systems were proven to be promising strategies for recalcitrant organics treatment, the direct interaction between NaClO and pollutants without explicit activation is quite limited. In this work, a revolutionary approach to degrade sulfathiazole (STZ) in aqueous and soil slurry by single NaClO without any activator was proposed. The results demonstrated that 100% and 94.11% of STZ could be degraded by 0.025 mM and 5 mM NaClO in water and soil slurry, respectively. The elimination of STZ was shown to involve superoxide anion (O2•-), chlorine oxygen radical (ClO•), and hydroxyl radical (•OH), according to quenching experiments and the analysis of electron paramagnetic resonance. The addition of Cl-, HCO3-, SO42-, and humic acid (HA) marginally impeded the decomposition of STZ, while NO3-, Fe3+, and Mn2+ facilitated the process. The NaClO process exhibited significant removal effectiveness at a neutral initial pH. Moreover, the NaClO facilitated application in various soil samples and water matrices, and the procedure was also successful in effectively eliminating a range of sulfonamides. The suggested NaClO degradation mechanism of STZ was based on the observed intermediates, and the majority of the products exhibited lower ecotoxicity than STZ. Besides, the experiment results by using X-ray diffraction (XRD) and a fourier transform infrared spectrometer (FTIR) indicated the negligible effects on the composition and structure of soil by the treatment of NaClO. Simultaneously, the experimental results also illustrated that the bioavailability of heavy metals and the physiochemical characteristics of the soil before and after the remediation did not change to a significant extent. Following the remediation of NaClO, the phytotoxicity tests showed reduced toxicity to wheat and cucumber seeds. As a result, treating soil and water contaminated with STZ by using NaClO was a reasonably practical and eco-friendly method.
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Affiliation(s)
- Longhui Qiu
- School of Geography and Environment, Key Laboratory of Poyang Lake Wetland and Watershed Research, Ministry of Education, Jiangxi Normal University, Nanchang, 330022, China
| | - Caixia Yan
- School of Geography and Environment, Key Laboratory of Poyang Lake Wetland and Watershed Research, Ministry of Education, Jiangxi Normal University, Nanchang, 330022, China
| | - Yue Zhang
- School of Geography and Environment, Key Laboratory of Poyang Lake Wetland and Watershed Research, Ministry of Education, Jiangxi Normal University, Nanchang, 330022, China
| | - Yabing Chen
- School of Geography and Environment, Key Laboratory of Poyang Lake Wetland and Watershed Research, Ministry of Education, Jiangxi Normal University, Nanchang, 330022, China
| | - Minghua Nie
- School of Geography and Environment, Key Laboratory of Poyang Lake Wetland and Watershed Research, Ministry of Education, Jiangxi Normal University, Nanchang, 330022, China.
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2
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Wang X, Lu Y, Yan Y, Wang R, Wang Y, Li H, Zhou L, Zheng G, Zhang Y. Pivotal role of intracellular oxidation by HOCl in simultaneously removing antibiotic resistance genes and enhancing dewaterability during conditioning of sewage sludge using Fe 2+/Ca(ClO) 2. WATER RESEARCH 2024; 254:121414. [PMID: 38461604 DOI: 10.1016/j.watres.2024.121414] [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: 11/25/2023] [Revised: 02/25/2024] [Accepted: 03/03/2024] [Indexed: 03/12/2024]
Abstract
Pre-acidification has been shown to be crucial in attenuating antibiotic resistance genes (ARGs) during the conditioning of sewage sludge. However, it is of great significance to develop alternative conditioning approaches that can effectively eliminate sludge-borne ARGs without relying on pre-acidification. This is due to the high investment costs and operational complexities associated with sludge pre-acidification. In this study, the effects of Fe2+/Ca(ClO)2 conditioning treatment on the enhancement of sludge dewaterability and the removal of ARGs were compared with other conditioning technologies. The dose effect and the associated mechanisms were also investigated. The findings revealed that Fe2+/Ca(ClO)2 conditioning treatment had the highest potential, even surpassing Fenton treatment with pre-acidification, in terms of eliminating the total ARGs. Moreover, the effectiveness of the treatment was found to be dose-dependent. This study also identified that the •OH radical reacted with extracellular polymeric substance (EPS) and extracellular ARGs, and the HOCl, the production of which was positively correlated with the dose of Fe2+/Ca(ClO)2, could infiltrate the EPS layer and diffuse into the cell of sludge flocs, inducing the oxidation of intracellular ARGs. Furthermore, this study observed a significant decrease in the predicted hosts of ARGs and MGEs in sludge conditioned with Fe2+/Ca(ClO)2, accompanied by a significant downregulation of metabolic pathways associated with ARG propagation, thereby contributing to the attenuation of sludge-borne ARGs. Based on these findings, it can be concluded that Fe2+/Ca(ClO)2 conditioning treatment holds great potential for the removal of sludge-borne ARGs while also enhancing sludge dewaterability, which mainly relies on the intracellular oxidation by HOCl.
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Affiliation(s)
- Xinxin Wang
- Department of Environmental Engineering, College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing 210095, China
| | - Yu Lu
- Department of Environmental Engineering, College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing 210095, China
| | - Yiwen Yan
- Department of Environmental Engineering, College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing 210095, China
| | - Ru Wang
- Department of Environmental Engineering, College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing 210095, China
| | - Yuhang Wang
- Department of Environmental Engineering, College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing 210095, China
| | - Hua Li
- Department of Civil Engineering, College of Urban Construction, Nanjing Tech University, Nanjing 211816, China.
| | - Lixiang Zhou
- Department of Environmental Engineering, College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing 210095, China; Jiangsu Collaborative Innovation Center for Solid Organic Waste Resource Utilization, Nanjing 210095, China
| | - Guanyu Zheng
- Department of Environmental Engineering, College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing 210095, China; Jiangsu Collaborative Innovation Center for Solid Organic Waste Resource Utilization, Nanjing 210095, China.
| | - Yifeng Zhang
- Department of Environmental and Resource Engineering, Technical University of Denmark, Lyngby DK-2800, Denmark
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Yuan H, Zhu N. Progress of improving waste activated sludge dewaterability: Influence factors, conditioning technologies and implications and perspectives. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 912:168605. [PMID: 37989393 DOI: 10.1016/j.scitotenv.2023.168605] [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: 09/15/2023] [Revised: 11/06/2023] [Accepted: 11/14/2023] [Indexed: 11/23/2023]
Abstract
Large amounts of waste activated sludge (WAS) as a by-product generated from the biological treatment in wastewater treatment plants (WWTPs) is of high moisture content (MC), organic pollutants, heavy metals and pathogenic bacteria, it may cause serious environmental ecological risk without appropriate disposal. More than one half of the total operation cost is accounted for sludge disposal in a WWTP. Dewatering is an essential and important step during the sludge treatment and disposal process for it could efficiently reduce its volume, and be beneficial to the subsequent treatment and disposal of sludge. However, sludge should be conditioned before mechanical dewatering because of its high hydrophilicity. In this work, it presented a comprehensive review on sludge dewatering including summarizing the dewaterability measurement indexes, affecting factors, conditioning technologies, the improvement mechanisms. Finally, based on the eventual disposal and low carbon emission target, the implications and perspectives development of sludge conditioning were discussed. Based on the above discussion, there is no unified theoretical insight of the improvement mechanism of sludge dewaterability. In addition, the relationship between the microstructure of organic matters in sludge floc and the dewaterability should be deepened. Especially, how to choose the optimal conditioning technology for sludge dewatering lies in the physical and chemical properties of sludge, however, the carbon emission of the conditioning and dewatering process also needs to be considered. Accordingly, green, low-cost and organic conditioning agents are the direction of future research, and the establishment of automatic operating system and real-time evaluation index system is the key challenge.
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Affiliation(s)
- Haiping Yuan
- Shanghai Engineering Research Center of Solid Waste Treatment and Resource Recovery, School of Environmental Science and Engineering, Shanghai Jiao Tong University, No.800 Dongchuan Road, Shanghai 200240, China
| | - Nanwen Zhu
- Shanghai Engineering Research Center of Solid Waste Treatment and Resource Recovery, School of Environmental Science and Engineering, Shanghai Jiao Tong University, No.800 Dongchuan Road, Shanghai 200240, China.
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4
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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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5
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Phosphorus removal from sewage by flocculated foamed lightweight aggregate: Performance optimisation, adsorption kinetics and mechanisms. Sep Purif Technol 2023. [DOI: 10.1016/j.seppur.2022.122458] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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Al-Mur BA, Pugazhendi A. A novel conversion of marine macroalgal biomass to biofuel (biohydrogen) via calcium hypochlorite induced dispersion. CHEMOSPHERE 2022; 308:136355. [PMID: 36087729 DOI: 10.1016/j.chemosphere.2022.136355] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/08/2022] [Revised: 08/10/2022] [Accepted: 09/02/2022] [Indexed: 06/15/2023]
Abstract
Environmental pollution due to the consumption of non-renewable energy lead the search for alternative eco-friendly renewable fuel. The study details the biohydrogen production efficiency by potential macroalgal (Ulva reticulata) biomass improved by a disperser combined with calcium hypochlorite pretreatment technology. Calcium hypochlorite was added to decrease the surface energy of the medium induced by sole disperser pretreatment. Optimum condition for algal disperser treatment was 10,000 rpm with 30 min as dispersion time. The specific energy spent for the disintegration of the macroalgal biomass was 1231.58 kJ/kg TS. COD solubilization rate of 11.79% was attained with mechanical pretreatment whereas increased to 20.23% with combined pretreatment. Combination of disperser with calcium hypochlorite significantly reduced the specific energy input spent to 500 kJ/kg TS. The amount of organic materials such as carbohydrates, proteins and lipids released were 680 mg/L, 283 mg/L and 136 mg/L respectively. Thus, the combinative pretreatment with disperser rotor speed (10,000 rpm) for pretreatment time (12 min) and calcium hypochlorite dosage (0.1 g/g) derived as optimum condition for effective solubilization of macroalgal biomass. Biohydrogen production potential was maximum in the macroalgae pretreated with both disperser and calcium hypochlorite recorded highest yield (54.6 mL H2/g COD) compared to the macroalgae pretreated with disperser alone (31.7 mL H2/g COD) and untreated macroalgae (11.5 mL H2/g COD).
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Affiliation(s)
- Bandar A Al-Mur
- Department of Environmental Science, Faculty of Meteorology, Environment and Arid Land Agriculture, King Abdulaziz University, Jeddah, Saudi Arabia
| | - Arulazhagan Pugazhendi
- Department of Marine Biology, Faculty of Marine Sciences, King Abdulaziz University, Jeddah, Saudi Arabia; Center of Excellence in Environmental Studies, King Abdulaziz University, Jeddah, 21589, Saudi Arabia.
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7
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Gao W, Song L, Wang Z, Xuan L. Pyrite activated peroxymonosulfate combined with as a physical-chemical conditioner modified biochar to improve sludge dewaterability: analysis of sludge floc structure and dewatering mechanism. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2022; 29:74725-74741. [PMID: 35639326 PMCID: PMC9153877 DOI: 10.1007/s11356-022-21074-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/29/2021] [Accepted: 05/20/2022] [Indexed: 06/15/2023]
Abstract
In this study, we proposed an advanced oxidation process of pyrite (FeS2) and peroxymonosulfate (PMS) and prepared a modified polyaluminum chloride biochar (P-BC). The motivation is to use the combination of FeS2 + PMS + P-BC to improve waste activated sludge (WAS) dewaterability. The method to improve the sludge dewatering effect with the combination of FeS2 + PMS + P-BC is as follows: in the first step, pour 0.75 g/g TSS FeS2 and 0.6 g/g TSS PMS into the sludge, and stir for 15 min. Then, add P-BC and stir for 5 min; complete the entire WAS processing process. The vacuum filtration test was used to evaluate the dehydration effect. The water content (Wc) and specific resistance to filtration (SRF) of the raw sludge can be reduced from the original values of 92% and 2.36 × 1013 m/kg to 67% and 9.89 × 1011 m/kg, respectively. The results showed that the combination of FeS2 + PMS + P-BC can effectively improve the sludge dewatering effect through oxidation. A laser particle size analyzer is used to observe changes in sludge particle size. The median diameter of sludge particles increased from 55.37 to 64.56 μm. A zeta analyzer to is used observe changes in sludge zeta potential. The zeta potential of sludge particles increased from - 15.8 to 0.4 mV. In the analysis of extracellular polymeric substances (EPS) of sludge, it was found that protein (PN) and polysaccharide (PS) in EPS decreased significantly. To further analyze the phenomenon of PN and PS drop, excitation-emission-matrix spectra (3D-EEM) was used. To observe the changes of sludge functional group, X-ray photoelectron spectroscopy was used. It was found that FeS2 + PMS + P-BC can destroy the functional groups of sludge, such as O-H, C-C, and O═C-NH- related to proteins and polysaccharides.
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Affiliation(s)
- Wenjian Gao
- School of Civil Engineering, Inner Mongolia University of Technology, Hohhot, 010051 China
| | - Lei Song
- School of Civil Engineering, Inner Mongolia University of Technology, Hohhot, 010051 China
| | - Zehao Wang
- School of Civil Engineering, Inner Mongolia University of Technology, Hohhot, 010051 China
| | - Lili Xuan
- School of Civil Engineering, Inner Mongolia University of Technology, Hohhot, 010051 China
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8
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Yu N, Mou A, Sun H, Liu Y. Anaerobic digestion of thickened waste activated sludge under calcium hypochlorite stress: Performance stability and microbial communities. ENVIRONMENTAL RESEARCH 2022; 212:113441. [PMID: 35561820 DOI: 10.1016/j.envres.2022.113441] [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: 03/16/2022] [Revised: 04/30/2022] [Accepted: 05/04/2022] [Indexed: 06/15/2023]
Abstract
Hypochlorite pretreatment has been proven effective in enhancing waste activated sludge (WAS) anaerobic digestion performances recently. In this study, two semi-continuous anaerobic sequencing batch reactors (ASBRs), one fed with Ca(ClO)2 pretreated thickened WAS (TWAS) and one with raw TWAS, were operated at mesophilic conditions (35 °C) for 145 days. Three loading shocks were introduced to each reactor to compare the performance stability and resilience between the digestion of Ca(ClO)2 pretreated TWAS and untreated TWAS. Microbial community shifts were quantified to reveal the microbiome responses to disturbances. The results suggested that 1% Ca(ClO)2 enhanced the digestion of TWAS by inactivating and transforming the biomass to more easily digested substrates. Co-occurrence network analysis revealed that the strongest interactions in the microbial community occurred in the steady state of TWAS anaerobic digestion.
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Affiliation(s)
- Najiaowa Yu
- Department of Civil and Environmental Engineering, University of Alberta, Edmonton, AB, T6G 1H9, Canada
| | - Anqi Mou
- Department of Civil and Environmental Engineering, University of Alberta, Edmonton, AB, T6G 1H9, Canada
| | - Huijuan Sun
- Department of Civil and Environmental Engineering, University of Alberta, Edmonton, AB, T6G 1H9, Canada
| | - Yang Liu
- Department of Civil and Environmental Engineering, University of Alberta, Edmonton, AB, T6G 1H9, Canada
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9
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Lv J, Tu M, Chen X, Li S, Li Y, Jiang J. Effect of potassium persulphate addition on sludge disintegration of a mesophilic anaerobic fermentation system. ENVIRONMENTAL TECHNOLOGY 2022; 43:1709-1722. [PMID: 33170751 DOI: 10.1080/09593330.2020.1849407] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/27/2020] [Accepted: 10/27/2020] [Indexed: 06/11/2023]
Abstract
Persulphates, an advanced oxidation process, has been recently used as an alternative pretreatment method to enhance short-chain fatty acids (SCFAs) yield from waste-activated sludge (WAS) anaerobic fermentation (AF). But so far, the effects of peroxydisulphate (PDS) dosages on mesophilic anaerobic fermentation are still not studied fully. Herein, we explored the influences of potassium PDS addition on mesophilic AF of WAS. Notably, the addition of PDS could drastically accelerate WAS solubilization and hydrolysis, which was proportional to the amount of PDS. The maximal total SCFAs yield of 249.14 mg chemical oxygen demand/L was obtained with 120 mg PDS/g suspended solids addition at 6 days of AF, which was 2.2-fold that of the control one. Tightly bound extracellular polymeric substances (EPSs) were transformed into loosely bound EPS and dissolved organic matters, and aromatic proteins and humic-like substances of EPSs were disintegrated, which were caused by the devastating effects of PDS treatments on EPSs disruption. The intracellular constituents of microbial cells in the sludge were released accordingly. As a result, there was release of soluble substrates derived from the disintegration of both EPSs and cells, the amounts of which were proportional to the dose of PDS. Moreover, microbial diversity and richness were both decreased in the presence of PDS, and the relative abundance of phyla Actinobacteria increased with the increase of the PDS dosage. In addition, the stability of sludge flocs was destroyed in the presence of PDS, the distribution of particle size tended to be small and dispersive, and dewaterability of the sludge was deteriorated.
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Affiliation(s)
- Jinghua Lv
- School of Environment, Henan Normal University, Xinxiang, People's Republic of China
- Key Laboratory of Yellow River and Huai River Water Environment and Pollution Control, Ministry of Education, Xinxiang, People's Republic of China
- Henan Key Laboratory for Environmental Pollution Control, Xinxiang, People's Republic of China
- International Joint Laboratory on Key Techniques in Water Treatment, Xinxiang, Henan Province, People's Republic of China
| | - Mengmiao Tu
- School of Environment, Henan Normal University, Xinxiang, People's Republic of China
| | - Xingyue Chen
- School of Environment, Henan Normal University, Xinxiang, People's Republic of China
| | - Suzhou Li
- School of Environment, Henan Normal University, Xinxiang, People's Republic of China
| | - Yunbei Li
- School of Environment, Henan Normal University, Xinxiang, People's Republic of China
- Key Laboratory of Yellow River and Huai River Water Environment and Pollution Control, Ministry of Education, Xinxiang, People's Republic of China
- Henan Key Laboratory for Environmental Pollution Control, Xinxiang, People's Republic of China
- International Joint Laboratory on Key Techniques in Water Treatment, Xinxiang, Henan Province, People's Republic of China
| | - Jishao Jiang
- School of Environment, Henan Normal University, Xinxiang, People's Republic of China
- Key Laboratory of Yellow River and Huai River Water Environment and Pollution Control, Ministry of Education, Xinxiang, People's Republic of China
- Henan Key Laboratory for Environmental Pollution Control, Xinxiang, People's Republic of China
- International Joint Laboratory on Key Techniques in Water Treatment, Xinxiang, Henan Province, People's Republic of China
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He X, He L, Lin Z, Zhou J, Shi S, Liu Y, Zhou J. Deep dewatering of activated sludge using composite conditioners of surfactant, acid and flocculant: The mechanism and dosage model. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 806:150899. [PMID: 34656594 DOI: 10.1016/j.scitotenv.2021.150899] [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: 07/21/2021] [Revised: 10/05/2021] [Accepted: 10/05/2021] [Indexed: 06/13/2023]
Abstract
To address the problem of difficult disposal caused by poor dewaterability of high-organic sludge in wastewater treatment plant, this study developed a sludge composite conditioner (SCC) consisting of sodium dodecyl sulfate (SDS), HCl and FeCl3. It has the potential to significantly improve the dewaterability of the high-organic sludge with the VSS/MLSS of 80%. The moisture content (MC) and bound water content of sludge were reduced from 98.00 to 59.65% and from 3.42 to 0.91 g/g dry sludge (DS) after being conditioned, respectively. The surfactant (SDS) promoted the dissolution of extracellular polymeric substances (EPS). The acid (HCl) enhanced the decomposition of the sludge flocs, making the insoluble EPS peel off and turn into the liquid phase. As a result, total EPS decreased by 52.70% compared to the original sludge. In addition, due to the neutralization effect of protons and FeCl3, the Zeta potential increased remarkably from -13.80 mV to -1.72 mV and the dispersed sludge particles formed during EPS dissolution process were re-flocculated, which increased the average size of the sludge particles. The ratio of proteins (PN)/polysaccharides (PS) also increased from 1.69 to 3.81. And a quantitative model of optimum dosage of SCC agents based on the influence of the sludge PS, PN and EPS content has been established, aiming to determine the dosage of each conditioner according to the properties of target sludge. In general, the SCC provided an effective pathway for sludge deep dewatering.
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Affiliation(s)
- Xuejie He
- Key Laboratory of the Three Gorges Reservoir Region's Eco-Environment, Ministry of Education, Chongqing University, Chongqing 400045, China
| | - Lei He
- Key Laboratory of the Three Gorges Reservoir Region's Eco-Environment, Ministry of Education, Chongqing University, Chongqing 400045, China
| | - Ziyuan Lin
- Key Laboratory of the Three Gorges Reservoir Region's Eco-Environment, Ministry of Education, Chongqing University, Chongqing 400045, China
| | - Jiong Zhou
- Key Laboratory of the Three Gorges Reservoir Region's Eco-Environment, Ministry of Education, Chongqing University, Chongqing 400045, China
| | - Shuohui Shi
- Key Laboratory of the Three Gorges Reservoir Region's Eco-Environment, Ministry of Education, Chongqing University, Chongqing 400045, China
| | - Yi Liu
- Key Laboratory of the Three Gorges Reservoir Region's Eco-Environment, Ministry of Education, Chongqing University, Chongqing 400045, China
| | - Jian Zhou
- Key Laboratory of the Three Gorges Reservoir Region's Eco-Environment, Ministry of Education, Chongqing University, Chongqing 400045, China.
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11
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Cheng X, Wang S, Huang W, Wang F, Fang S, Ge R, Zhang Q, Zhang L, Du W, Fang F, Feng Q, Cao J, Luo J. Current status of hypochlorite technology on the wastewater treatment and sludge disposal: Performance, principals and prospects. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 803:150085. [PMID: 34525771 DOI: 10.1016/j.scitotenv.2021.150085] [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: 06/01/2021] [Revised: 08/29/2021] [Accepted: 08/29/2021] [Indexed: 06/13/2023]
Abstract
As cost-effective and high-efficient oxidants, the hypochlorite chemicals have been widely utilized for bleaching and disinfection. However, its potential applications in wastewater treatment and sludge disposal were less concerned. This paper mainly summarized the state-of-the-art applications of hypochlorite technology in wastewater and sludge treatment based on the main influencing factors and potential mechanisms of hypochlorite treatment. The results indicated that the hypochlorite approaches were not only effective in pollutants removal and membrane fouling mitigation for wastewater treatment, but also contributed to sludge dewatering and resource recovery for sludge disposal. The ClO- and large generated free active radicals (i.e., reactive chlorine species and reactive oxygen species), which possessed strong oxidative ability, were the primary contributors to the pollutants decomposition, and colloids/microbes flocs disintegration during the hypochlorite treatment process. The performance of hypochlorite treatment was highly associated with various factors (i.e., pH, temperature, hypochlorite types and dosage). In combination with the reasonable activators (i.e., Fe2+ and ultraviolet), auxiliary agents, and innovative processes (i.e., hydrothermal and electro-oxidation), the operational performance of hypochlorite technology could be further enhanced. Finally, the feasibility and benefits of hypochlorite application for wastewater and sludge treatment were analyzed, and the existing challenges and future research efforts that need to be made have also prospected. The review can hopefully provide a theoretical basis and technical guidance to extend the application of hypochlorite technology for wastewater treatment and sludge disposal on large scale.
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Affiliation(s)
- Xiaoshi Cheng
- Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Ministry of Education, Hohai University, Nanjing 210098, China; College of Environment, Hohai University, Nanjing 210098, China
| | - Suna Wang
- Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Ministry of Education, Hohai University, Nanjing 210098, China; College of Environment, Hohai University, Nanjing 210098, China
| | - Wenxuan Huang
- Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Ministry of Education, Hohai University, Nanjing 210098, China; College of Environment, Hohai University, Nanjing 210098, China
| | - Feng Wang
- Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Ministry of Education, Hohai University, Nanjing 210098, China; College of Environment, Hohai University, Nanjing 210098, China
| | - Shiyu Fang
- Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Ministry of Education, Hohai University, Nanjing 210098, China; College of Environment, Hohai University, Nanjing 210098, China
| | - Ran Ge
- College of Harbor, Coastal and Offshore Engineering, Hohai University, Nanjing 210098, China
| | - Qin Zhang
- Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Ministry of Education, Hohai University, Nanjing 210098, China; College of Environment, Hohai University, Nanjing 210098, China
| | - Le Zhang
- Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Ministry of Education, Hohai University, Nanjing 210098, China; College of Environment, Hohai University, Nanjing 210098, China
| | - Wei Du
- Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Ministry of Education, Hohai University, Nanjing 210098, China; College of Environment, Hohai University, Nanjing 210098, China
| | - Fang Fang
- Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Ministry of Education, Hohai University, Nanjing 210098, China; College of Environment, Hohai University, Nanjing 210098, China
| | - Qian Feng
- Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Ministry of Education, Hohai University, Nanjing 210098, China; College of Environment, Hohai University, Nanjing 210098, China
| | - Jiashun Cao
- Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Ministry of Education, Hohai University, Nanjing 210098, China; College of Environment, Hohai University, Nanjing 210098, China
| | - Jingyang Luo
- Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Ministry of Education, Hohai University, Nanjing 210098, China; College of Environment, Hohai University, Nanjing 210098, China.
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12
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Yu N, Sun H, Mou A, Liu Y. Calcium hypochlorite enhances the digestibility of and the phosphorus recovery from waste activated sludge. BIORESOURCE TECHNOLOGY 2021; 340:125658. [PMID: 34332447 DOI: 10.1016/j.biortech.2021.125658] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/03/2021] [Revised: 07/19/2021] [Accepted: 07/22/2021] [Indexed: 06/13/2023]
Abstract
Waste activated sludge (WAS) can be treated using anaerobic digestion (AD) for biogas recovery and volume reduction. However, the poor digestibility and hydrolysis of WAS limit AD applications. The current study investigated the feasibility of applying calcium hypochlorite as a WAS pretreatment strategy to improve AD treatment efficiency using laboratory reactors. The results showed that pretreatment with 5 - 20% Ca(ClO)2 (total suspended solids basis) significantly enhanced WAS anaerobic digestibility, and led to significantly enhanced methane production rate and biomethane yield comparing to the AD of raw WAS (P < 0.05). Low Ca(ClO)2 pretreatment (5 - 10%) significantly enhanced digestion efficiency, which can be attributed to the development of fermentative and syntrophic bacteria. However, high Ca(ClO)2 doses (>20%) reduced microbial activities, leading to slow release of dissolved organic compounds and prolonged methane production lag phase. In addition, high Ca(ClO)2 removed 82.7% of the initial phosphate by calcium-phosphate binding, reducing the phosphorus in liquid digestate.
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Affiliation(s)
- Najiaowa Yu
- Department of Civil and Environmental Engineering, University of Alberta, Edmonton, Alberta T6G 1H9, Canada
| | - Huijuan Sun
- Department of Civil and Environmental Engineering, University of Alberta, Edmonton, Alberta T6G 1H9, Canada
| | - Anqi Mou
- Department of Civil and Environmental Engineering, University of Alberta, Edmonton, Alberta T6G 1H9, Canada
| | - Yang Liu
- Department of Civil and Environmental Engineering, University of Alberta, Edmonton, Alberta T6G 1H9, Canada.
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13
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Bei Li Y, Li Song J, Jing Yao Q, Xu Chen Z, Wei Y, Long Li H, Xiao Wang M, Jing Wang B, Min Zhou J. Effects of dissolved oxygen on the sludge dewaterability and extracellular polymeric substances distribution by bioleaching. CHEMOSPHERE 2021; 281:130906. [PMID: 34029968 DOI: 10.1016/j.chemosphere.2021.130906] [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: 11/25/2020] [Revised: 05/11/2021] [Accepted: 05/13/2021] [Indexed: 06/12/2023]
Abstract
Bioleaching is a biological conditioning technology for sludge, which not only improves sludge dewatering performance but also removes heavy metals from sludge. As the bioleaching process is a comprehensive biological and chemical process, it is necessary to explore the effects of dissolved oxygen (DO) concentrations on bioleaching efficiency. Three bioleaching experiments with different DO concentrations (T1: 0.8-3.1 mg/L, T2: 3.1-5.5 mg/L, T3: 5.5-7.5 mg/L) were conducted for five days. The sludge dewatering efficiency was evaluated using capillary suction time (CST) and specific resistance to filtration (SRF). The relationship between sludge dewaterability and extracellular polymeric substance (EPS) fraction distribution was investigated. In the treatment with the highest DO concentration, the minimum values of SRF and CST were 4.31 × 1011 m/kg and 13.5 s, which occurred earlier than the treatment with the lower DO concentrations by approximately 24-48 h. A significant decrease (83.4-93.2%) in tightly bound EPS (TB-EPS) protein (PN) was observed in all treatments, while a positive correlation (r = 0.924, P < 0.01) was observed between SRF and PN content in TB-EPS. A relatively higher abundance of Acidithiobacillus was found with the increase in DO concentration. Additionally, other genera including Metallibacterium, Alicyclobacillus, Acidibacter, Acidocella, and Luteococcus also played important roles in EPS biodegradation. These results revealed that increasing the DO concentration could improve sludge dewatering performance and heavy metal removal by enhancing bioleaching microbial activity, the degradation of PN in TB-EPS, and sludge floc fragmentation, but only if sufficient energy sources were provided.
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Affiliation(s)
- Yun Bei Li
- School of Environment, Henan Normal University, China; Key Laboratory of Yellow River and Huai River Water Environment and Pollution Control, Ministry of Education, China; Henan Key Laboratory for Environmental Pollution Control, China.
| | - Jun Li Song
- School of Environment, Henan Normal University, China
| | - Qian Jing Yao
- School of Environment, Henan Normal University, China
| | - Ze Xu Chen
- School of Environment, Henan Normal University, China
| | - Yi Wei
- School of Environment, Henan Normal University, China
| | - Hai Long Li
- School of Environment, Henan Normal University, China
| | | | | | - Jia Min Zhou
- School of Environment, Henan Normal University, China
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14
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Yang M, Chen J, Wang X, Sun Y, Xu Y, Liu Q. Enhancement of phosphorus release from waste activated sludge by electrochemical treatment. ENVIRONMENTAL TECHNOLOGY 2021; 42:3698-3706. [PMID: 32134366 DOI: 10.1080/09593330.2020.1739145] [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: 05/21/2019] [Accepted: 02/29/2020] [Indexed: 06/10/2023]
Abstract
The enhancement of phosphorus (P) released from waste activated sludge (WAS) by electrochemical treatment was investigated in this study. Results showed that the concentration of orthophosphate (ortho-P) and organic phosphorus (OP) in liquid both increased after electrochemical treatment. The ortho-P and OP concentration reached a maximum of 5.020 and 1.888 mg/L under the optimal condition respectively (voltage of 4.5 V and time of 60 min), which were 2.86 and 4.93 times higher than that in raw sludge. Meanwhile, the role of extracellular polymeric substances (EPS) in this process was also studied. The variation trends of P-release in tightly bound EPS (TB-EPS) and loosely bound EPS (LB-EPS) were different. In TB-EPS, the concentration of total phosphorus (TP) and ortho-P decreased when the voltage increased. In contrast, the concentration of TP and ortho-P in LB-EPS increased and reached the maximum under the optimal condition. Released metal ions (Ca, Mg, Fe, and Al) had some effects on P-release both in liquid and EPS, which indicated that EPS played an important role. SCOD and TSS revealed that the disintegration of sludge was also enhanced by electrochemical treatment. Additionally, the P fractions in sludge phase suggested that OP was more likely to be released in liquid phase.
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Affiliation(s)
- Min Yang
- School of Environmental and Chemical Engineering, Shanghai University, Shanghai, People's Republic of China
| | - Jingyan Chen
- School of Environmental and Chemical Engineering, Shanghai University, Shanghai, People's Republic of China
| | - Xin Wang
- School of Environmental and Chemical Engineering, Shanghai University, Shanghai, People's Republic of China
| | - Ying Sun
- School of Environmental and Chemical Engineering, Shanghai University, Shanghai, People's Republic of China
| | - Yunfeng Xu
- School of Environmental and Chemical Engineering, Shanghai University, Shanghai, People's Republic of China
| | - Qiang Liu
- School of Environmental and Chemical Engineering, Shanghai University, Shanghai, People's Republic of China
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15
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Xu Y, Hu F, Wang X, Qu Y, Xu L, Liu Q. Improvement of phosphorus release from sludge by combined electrochemical-EDTA treatment. WATER SCIENCE AND TECHNOLOGY : A JOURNAL OF THE INTERNATIONAL ASSOCIATION ON WATER POLLUTION RESEARCH 2021; 83:1824-1833. [PMID: 33905355 DOI: 10.2166/wst.2021.107] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
In this paper, combined with the addition of ethylenediaminetetraacetic acid (EDTA), the electrochemical treatment of waste activated sludge (WAS) was investigated to explore its effect on the release of phosphorus (P) from WAS. The results showed that during the electrochemical treatment, the addition of EDTA could significantly promote the release of P from the WAS to the supernatant, the optimal amount of EDTA was 0.4 g/g total suspended solids (TSS), when the release of total dissolved phosphorus (TDP), organic phosphorus (OP) and molybdate reactive phosphorus (PO43--P) were 187.30, 173.84 and 13.46 mg/L, respectively. OP was the most likely form of P to be released during this process. Moreover, combined electrochemical-EDTA treatment could promote the release of P and metal ions from extracellular polymeric substances (EPSs) to the supernatant, and increase the solubility and disintegration of sludge. EDTA chelated the metal ions of sludge flocs and phosphate precipitates to cause sludge floc decomposition, thereby promoting the release of P from WAS.
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Affiliation(s)
- Yunfeng Xu
- School of Environmental and Chemical Engineering, Shanghai University, No. 99, Shangda Rd, Shanghai 200444, China E-mail:
| | - Fanglu Hu
- School of Environmental and Chemical Engineering, Shanghai University, No. 99, Shangda Rd, Shanghai 200444, China E-mail:
| | - Xin Wang
- School of Environmental and Chemical Engineering, Shanghai University, No. 99, Shangda Rd, Shanghai 200444, China E-mail:
| | - Yangwei Qu
- School of Environmental and Chemical Engineering, Shanghai University, No. 99, Shangda Rd, Shanghai 200444, China E-mail:
| | - Lu Xu
- School of Environmental and Chemical Engineering, Shanghai University, No. 99, Shangda Rd, Shanghai 200444, China E-mail:
| | - Qiang Liu
- School of Environmental and Chemical Engineering, Shanghai University, No. 99, Shangda Rd, Shanghai 200444, China E-mail:
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16
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Yang N, Xiao H, Pi K, Fang J, Liu S, Chen Y, Shi Y, Zhang H, Gerson AR, Liu D. Synchronization of dehydration and phosphorous immobilization for river sediment by calcified polyferric sulfate pretreatment. CHEMOSPHERE 2021; 269:129403. [PMID: 33385664 DOI: 10.1016/j.chemosphere.2020.129403] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/08/2020] [Revised: 10/29/2020] [Accepted: 12/20/2020] [Indexed: 06/12/2023]
Abstract
Disposal of dredged river sediment requires decreases in both water content for reduction in disposal area, and the amount of eutrophication pollutants at risking of leaching. The effects of CaCl2, polyferric sulfate (PFS) and calcified polyferric sulfate (CaPFS) on dewatering and phosphorus immobilization were examined. Upon CaPFS dosage of 1.88 mg Ca + Fe kg-1 raw sediment (RS) the moisture content of the sediment was 41.1 wt% after pressure filtration, with filtrate dissolved inorganic phosphorus (DIP) of 6.1 mg L-1; better outcomes than for equivalent dosages of CaCl2 or PFS. On CaPFS dosage of 4.98 mg Ca + Fe kg-1 RS, DIP in the filtrate was <0.5 mg L-1. Dosages of CaCl2 and PFS required to achieve <0.5 mg L-1 DIP were 6.79 mg Ca kg-1 RS and 5.64 mg Fe kg-1 RS. CaPFS aids particle surface charge neutralization and sweep flocculation by polymeric iron, improving dehydration efficiency. Synergistic effects of aqueous Ca and Fe promote P stability reducing DIP mobility. For treatment of 10000 m3 of this dredged sediment, CaPFS has the potential to reduce the discharge of eutrophicated water by 74 ± 6% compared with PAC + PAM conditioning, demonstrating the promising application of CaPFS conditioning.
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Affiliation(s)
- Nan Yang
- School of Resource and Environmental Engineering, Hubei University of Technology, Wuhan, Hubei, 430068, China.
| | - Hang Xiao
- School of Resource and Environmental Engineering, Hubei University of Technology, Wuhan, Hubei, 430068, China.
| | - Kewu Pi
- School of Resource and Environmental Engineering, Hubei University of Technology, Wuhan, Hubei, 430068, China.
| | - Jing Fang
- School of Resource and Environmental Engineering, Hubei University of Technology, Wuhan, Hubei, 430068, China.
| | - Shuze Liu
- School of Resource and Environmental Engineering, Hubei University of Technology, Wuhan, Hubei, 430068, China.
| | - Yuhan Chen
- School of Resource and Environmental Engineering, Hubei University of Technology, Wuhan, Hubei, 430068, China.
| | - Yafei Shi
- School of Resource and Environmental Engineering, Hubei University of Technology, Wuhan, Hubei, 430068, China.
| | - Huiqin Zhang
- School of Resource and Environmental Engineering, Hubei University of Technology, Wuhan, Hubei, 430068, China.
| | - Andrea R Gerson
- Blue Minerals Consultancy, Wattle Grove, Tasmania, 7109, Australia.
| | - Defu Liu
- School of Resource and Environmental Engineering, Hubei University of Technology, Wuhan, Hubei, 430068, China.
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17
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Wang Q, Song L, Hui K, Song H. Iron powder activated peroxymonosulfate combined with waste straw to improve sludge dewaterability. ENVIRONMENTAL TECHNOLOGY 2021; 42:1302-1311. [PMID: 31487232 DOI: 10.1080/09593330.2019.1665111] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/10/2019] [Accepted: 08/31/2019] [Indexed: 06/10/2023]
Abstract
In an activated sludge system, the high hydrophilicity of extracellular polymeric substances (EPS) and the high compressibility of sludge greatly hinder sludge dewatering. A new method for improving the dehydration of waste activated sludge was explored by using iron powder activated peroxomonosulfate combined with waste straw (Fe0+PMS + WS). Specific resistance to filtration (SRF) and water content (Wc) were used to characterize the dewatering performance of sludge. Under the optimal measurement, Wc and SRF were significantly reduced. To reveal the synergistic effect of this joint treatment, zeta potential, particle size distribution, three-dimension excitation emission matrix (3D-EEM) fluorescence spectroscopy, bound water content analysis, and scanning electron microscopy (SEM) were used to investigate the mechanism of sludge dewatering. Results showed that the tightly bound EPS (TB-EPS) was oxidized by sulfate radicals (SO4-∙) to loose bound EPS (LB-EPS) and soluble EPS(S-EPS). SEM analysis displayed that the Fe0+PMS + WS combination regulated the formation of a more porous sludge filter cake structure. In addition, the low calorific value of the dewatered sludge after 12 h in open air was significantly increased, and the Wc of the dewatered sludge cake was reduced to 25%. These parameters were beneficial to the subsequent disposal of sludge.
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Affiliation(s)
- Qian Wang
- School of Civil Engineering, Inner Mongolia University of Technology, Hohhot, People's Republic of China
| | - Lei Song
- School of Civil Engineering, Inner Mongolia University of Technology, Hohhot, People's Republic of China
| | - Kai Hui
- School of Civil Engineering, Inner Mongolia University of Technology, Hohhot, People's Republic of China
| | - Hongwei Song
- School of Civil Engineering, Inner Mongolia University of Technology, Hohhot, People's Republic of China
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18
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Jessieleena AA, M P, Mp S. Comparative study of Fenton, Fe 2+/NaOCl and Fe 2+/(NH 4) 2S 2O 8 on tannery sludge dewaterability, degradability of organics and leachability of chromium. JOURNAL OF HAZARDOUS MATERIALS 2021; 402:123495. [PMID: 32739724 DOI: 10.1016/j.jhazmat.2020.123495] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/29/2020] [Revised: 06/23/2020] [Accepted: 07/09/2020] [Indexed: 06/11/2023]
Abstract
In this work, a comparative analysis of Fenton, Fe2+/NaOCl and Fe2+/(NH4)2S2O8 assisted advanced oxidation processes was carried out to study its efficacy in enhancing tannery chemical sludge dewaterability. Experimental results showed that, after conditioning of sludge at optimum pH, oxidant and catalyst dosage, capillary suction time (CST) was decreased by 75 ± 5 % and moisture content of sludge cake (M.Ccake) was reduced to 74 ± 2 % for all processes at 10 min reaction time. Among the three processes, Fe2+/(NH4)2S2O8 process was noted to have larger impact on the breakdown of sludge cells, which is reflected in terms of its highest amount of total organic carbon, protein and total dissolved solids present in the separated sludge fractions. In addition, Fe2+/(NH4)2S2O8 process was also observed to leach out largest fraction say 73.3 % of chromium present in the raw sludge into the treated sludge filtrate. The investigation carried out through zeta potential and scanning electron microscopy reveals the role of a two-step mechanism, namely oxidation followed by coagulation in enhancing the sludge dewaterability. Further studies on the possibility of utilizing dried treated sludge as biomass fuel could be carried out.
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Affiliation(s)
- A Angel Jessieleena
- Department of Environmental and Water Resources Engineering, School of Civil Engineering, Vellore Institute of Technology, Vellore, 632014, Tamil Nadu, India.
| | - Priyanka M
- Department of Environmental and Water Resources Engineering, School of Civil Engineering, Vellore Institute of Technology, Vellore, 632014, Tamil Nadu, India.
| | - Saravanakumar Mp
- Department of Environmental and Water Resources Engineering, School of Civil Engineering, Vellore Institute of Technology, Vellore, 632014, Tamil Nadu, India.
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19
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Shi Z, Pi K, Huang X, Shi Y, Chen Z, Tang R, Hu Z, Gerson AR, Liu D. Enhanced dewater efficiency for river sediment by top-to-bottom water transmitting channels with different materials. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2020; 27:29228-29238. [PMID: 32436088 DOI: 10.1007/s11356-020-09250-w] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/18/2020] [Accepted: 05/11/2020] [Indexed: 06/11/2023]
Abstract
Artificial top-to-bottom water transmitting channels made of threads of wool blend (WT), cotton (CT), flax (FT), and polyethylene (PET) were used to enhance the dewater efficiency for river sediment. In addition, the disordered channels composed of 3-mm-long WT segments mixed randomly into the river sediment were also employed. The most effective dewatering channels were found to be top-to-bottom WT channels with water absorption capacity of 8.7 ± 0.5 g · g-1 and volume compressibility of 2.94 ± 0.11. On the application of 0.1 MPa pressure to the mud surface, with initial water content of 60.0 ± 0.2 wt%, the water content obtained with channel material weight 0.411 wt% dry solids and channel to a mud cake height ratio of 0.95 upon 90-min dewatering was 39.6 ± 0.7 wt% with enhanced dewaterability, compared to that without channel addition, of 74.9 ± 0.9 kg · kg-1 · h-1. Using the same parameters, enhanced dewaterability was only 69.1 ± 0.3, 55.2 ± 2.8, and 9.1 ± 0.9 kg · kg-1 · h-1 for CT, FT, and PET channels, respectively. Moreover, the final water content of the mud cake dewatered in the presence of disordered WT channels at dosage 1.10 wt% was 49.8 ± 0.7 wt% with enhanced dewaterability of 5.9 ± 0.5 kg · kg-1 · h-1 only. These demonstrate that the compressibility of the water transmitting material is the main factor affecting dewatering efficiency with the water absorption capacity also being important.
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Affiliation(s)
- Zhuo Shi
- School of Civil and Environmental Engineering, Hubei University of Technology, Wuhan, 430068, Hubei, China
| | - Kewu Pi
- School of Civil and Environmental Engineering, Hubei University of Technology, Wuhan, 430068, Hubei, China.
| | - Xuanming Huang
- School of Civil and Environmental Engineering, Hubei University of Technology, Wuhan, 430068, Hubei, China
| | - Yafei Shi
- School of Civil and Environmental Engineering, Hubei University of Technology, Wuhan, 430068, Hubei, China
| | - Ziwen Chen
- School of Civil and Environmental Engineering, Hubei University of Technology, Wuhan, 430068, Hubei, China
| | - Ruyu Tang
- School of Civil and Environmental Engineering, Hubei University of Technology, Wuhan, 430068, Hubei, China
| | - Zehui Hu
- School of Civil and Environmental Engineering, Hubei University of Technology, Wuhan, 430068, Hubei, China
| | - Andrea R Gerson
- Blue Minerals Consultancy, Wattle Grove, Tasmania, 7109, Australia
| | - Defu Liu
- School of Civil and Environmental Engineering, Hubei University of Technology, Wuhan, 430068, Hubei, China
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20
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Chen D, Dou Y, Tang Q, Huang Y, Song M, Peng F. New Insight on the Combined Effects of Hydrothermal Treatment and FeSO 4/Ca(ClO) 2 Oxidation for Sludge Dewaterability Improvement: Moisture Distribution and Noncovalent Interaction Calculation. ACS OMEGA 2020; 5:15891-15900. [PMID: 32656409 PMCID: PMC7345395 DOI: 10.1021/acsomega.0c00995] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/05/2020] [Accepted: 06/04/2020] [Indexed: 06/11/2023]
Abstract
A combination of hydrothermal treatment and FeSO4/Ca(ClO)2 oxidation was developed in our previous work and was proved to be significantly useful for improving the sludge dewaterability. The dewatering mechanism of the sludge after the combined treatment of hydrothermal treatment and FeSO4·7H2O/Ca(ClO)2 was obtained for the first time based on the moisture distribution analysis. Moreover, the noncovalent interaction between the hydrophilic sites of sludge EPS in sludge and water molecules was studied for the first time by using density functional theory. The electrostatic potentials of three representative EPS molecules, that is, dextran, poly-gamma-glutamate, and poly-l-lysine, were calculated and analyzed. AIM and RDG of the representative EPS·water complex models were calculated to study the noncovalent interaction mechanism. The moisture distribution and noncovalent interactions analyzed in this paper will provide information for improving sludge dewatering performance.
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Affiliation(s)
- Dandan Chen
- Engineering
Laboratory for Energy System Process Conversion & Emission Control
Technology of Jiangsu Province, School of Energy & Mechanical
Engineering, Nanjing Normal University, Nanjing 210023, China
- Key
Laboratory of Energy Thermal Conversion and Control of Ministry of
Education, School of Energy and Environment, Southeast University, Nanjing 210096, China
- China
Construction Power and Environment Engineering Co., LTD, Nanjing 210017, China
| | - Yuhao Dou
- Engineering
Laboratory for Energy System Process Conversion & Emission Control
Technology of Jiangsu Province, School of Energy & Mechanical
Engineering, Nanjing Normal University, Nanjing 210023, China
| | - Qin Tang
- Engineering
Laboratory for Energy System Process Conversion & Emission Control
Technology of Jiangsu Province, School of Energy & Mechanical
Engineering, Nanjing Normal University, Nanjing 210023, China
| | - Yaji Huang
- Key
Laboratory of Energy Thermal Conversion and Control of Ministry of
Education, School of Energy and Environment, Southeast University, Nanjing 210096, China
| | - Min Song
- Key
Laboratory of Energy Thermal Conversion and Control of Ministry of
Education, School of Energy and Environment, Southeast University, Nanjing 210096, China
| | - Feirong Peng
- China
Construction Power and Environment Engineering Co., LTD, Nanjing 210017, China
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21
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Luo J, Huang W, Zhang Q, Guo W, Wu Y, Feng Q, Fang F, Cao J, Su Y. Effects of different hypochlorite types on the waste activated sludge fermentation from the perspectives of volatile fatty acids production, microbial community and activity, and characteristics of fermented sludge. BIORESOURCE TECHNOLOGY 2020; 307:123227. [PMID: 32229411 DOI: 10.1016/j.biortech.2020.123227] [Citation(s) in RCA: 34] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/18/2020] [Revised: 03/16/2020] [Accepted: 03/19/2020] [Indexed: 06/10/2023]
Abstract
The effects of different hypochlorite types (namely Ca(OCl)2 and NaOCl) on the waste activated sludge (WAS) anaerobic fermentation, and microbial community and activity were investigated. The results indicated that both Ca(OCl)2 and NaOCl contributed to volatile fatty acids (VFAs) production by simultaneously enhancing the solubilization, hydrolysis and acidification processes. The maximal VFAs was respectively 1379.5 (at 10 d) and 1621.5 (at 8 d) mg COD/L at the optimal dose of NaOCl and Ca(OCl)2 while it was merely 157.4 (at 6 d) mg COD/L in the control. However, the Ca(OCl)2 might affect the anaerobic process in a continuous mode while the NaOCl was relatively transient, which caused distinctive influences on the microbial structure and activity, and subsequently VFAs production in WAS fermentation systems. Moreover, Ca(OCl)2 treatments showed advantages over NaOCl on WAS dewatering and VSS reduction, implying the superiority of utilizing Ca(OCl)2 as additives for WAS disposal.
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Affiliation(s)
- Jingyang Luo
- Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Ministry of Education, Hohai University, 1 Xikang Road, Nanjing 210098, China; College of Environment, Hohai University, 1 Xikang Road, Nanjing 210098, China; Guohe Environmental Research Institute (Nanjing) Co., Ltd, Nanjing 211599, China
| | - Wenxuan Huang
- Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Ministry of Education, Hohai University, 1 Xikang Road, Nanjing 210098, China; College of Environment, Hohai University, 1 Xikang Road, Nanjing 210098, China
| | - Qin Zhang
- Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Ministry of Education, Hohai University, 1 Xikang Road, Nanjing 210098, China; College of Environment, Hohai University, 1 Xikang Road, Nanjing 210098, China
| | - Wen Guo
- Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Ministry of Education, Hohai University, 1 Xikang Road, Nanjing 210098, China; College of Environment, Hohai University, 1 Xikang Road, Nanjing 210098, China
| | - Yang Wu
- Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Ministry of Education, Hohai University, 1 Xikang Road, Nanjing 210098, China; College of Environment, Hohai University, 1 Xikang Road, Nanjing 210098, China
| | - Qian Feng
- Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Ministry of Education, Hohai University, 1 Xikang Road, Nanjing 210098, China; College of Environment, Hohai University, 1 Xikang Road, Nanjing 210098, China; Guohe Environmental Research Institute (Nanjing) Co., Ltd, Nanjing 211599, China
| | - Fang Fang
- Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Ministry of Education, Hohai University, 1 Xikang Road, Nanjing 210098, China; College of Environment, Hohai University, 1 Xikang Road, Nanjing 210098, China; Guohe Environmental Research Institute (Nanjing) Co., Ltd, Nanjing 211599, China
| | - Jiashun Cao
- Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Ministry of Education, Hohai University, 1 Xikang Road, Nanjing 210098, China; College of Environment, Hohai University, 1 Xikang Road, Nanjing 210098, China; Guohe Environmental Research Institute (Nanjing) Co., Ltd, Nanjing 211599, China
| | - Yinglong Su
- Shanghai Key Lab for Urban Ecological Processes and Eco-Restoration, School of Ecological and Environmental Sciences, East China Normal University, Shanghai 200241, China.
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Zhang Q, Wu Y, Luo J, Cao J, Kang C, Wang S, Li K, Zhao J, Aleem M, Wang D. Enhanced volatile fatty acids production from waste activated sludge with synchronous phosphorus fixation and pathogens inactivation by calcium hypochlorite stimulation. THE SCIENCE OF THE TOTAL ENVIRONMENT 2020; 712:136500. [PMID: 31931205 DOI: 10.1016/j.scitotenv.2020.136500] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/15/2019] [Revised: 12/10/2019] [Accepted: 01/01/2020] [Indexed: 06/10/2023]
Abstract
An efficient approach for synchronous volatile fatty acids (VFAs) promotion, phosphorus fixation and pathogens inactivation during waste activated sludge (WAS) anaerobic fermentation was achieved with optimal calcium hypochlorite (Ca(ClO)2) stimulation. The maximal VFAs were 3.6 folds of control in reactors with 0.01 g Ca(ClO)2/g TSS addition. The low dosage of Ca(ClO)2 enhanced WAS solubilization and hydrolysis by disrupting the extracellular polymeric substance (EPS) effectively. Sufficient substrates for fermentative bacteria were thereby provided with the maintenance of acceptable microbial activity and viability. However, high dosage of Ca(ClO)2 deteriorated the performance of anaerobic fermentation due to its strong oxidative ability, resulting in cell lysis greatly. Moreover, the largely released phosphorus during WAS fermentation was effectively precipitated and removed by the combination of Ca2+ at 0.01 g Ca(ClO)2/g TSS dosage. In addition, Ca(ClO)2 had distinguished effects on pathogens inactivation. The simultaneous phosphorus fixation and pathogens reduction during VFAs production increased the utilization value of fermentation liquid and benefitted the further disposal of fermented sludge.
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Affiliation(s)
- Qin Zhang
- Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Ministry of Education, Hohai University, 1 Xikang Road, Nanjing 210098, PR China; College of Environment, Hohai University, 1 Xikang Road, Nanjing 210098, PR China
| | - Yang Wu
- Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Ministry of Education, Hohai University, 1 Xikang Road, Nanjing 210098, PR China; College of Environment, Hohai University, 1 Xikang Road, Nanjing 210098, PR China
| | - Jingyang Luo
- Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Ministry of Education, Hohai University, 1 Xikang Road, Nanjing 210098, PR China; College of Environment, Hohai University, 1 Xikang Road, Nanjing 210098, PR China; Guohe Environmental Research Institute (Nanjing) Co., Ltd, Nanjing 211599, PR China.
| | - Jiashun Cao
- Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Ministry of Education, Hohai University, 1 Xikang Road, Nanjing 210098, PR China; College of Environment, Hohai University, 1 Xikang Road, Nanjing 210098, PR China; Guohe Environmental Research Institute (Nanjing) Co., Ltd, Nanjing 211599, PR China
| | - Chaojie Kang
- Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Ministry of Education, Hohai University, 1 Xikang Road, Nanjing 210098, PR China; College of Environment, Hohai University, 1 Xikang Road, Nanjing 210098, PR China
| | - Suna Wang
- Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Ministry of Education, Hohai University, 1 Xikang Road, Nanjing 210098, PR China; College of Environment, Hohai University, 1 Xikang Road, Nanjing 210098, PR China
| | - Keyan Li
- Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Ministry of Education, Hohai University, 1 Xikang Road, Nanjing 210098, PR China; College of Environment, Hohai University, 1 Xikang Road, Nanjing 210098, PR China
| | - Jianan Zhao
- Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Ministry of Education, Hohai University, 1 Xikang Road, Nanjing 210098, PR China; College of Environment, Hohai University, 1 Xikang Road, Nanjing 210098, PR China
| | - Muhammad Aleem
- Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Ministry of Education, Hohai University, 1 Xikang Road, Nanjing 210098, PR China; College of Environment, Hohai University, 1 Xikang Road, Nanjing 210098, PR China
| | - Dongbo Wang
- College of Environmental Science and Engineering, Hunan University, Changsha 410082, PR China
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Wu X, Li X, Yang Q, Xu Q, Tao Z, Huang X, Wu Y, Tao L, Pi Z, Chen Z, Wang D. Effect of citric acid on extracellular polymeric substances disruption and cell lysis in the waste activated sludge by pH regulation. BIORESOURCE TECHNOLOGY 2020; 302:122859. [PMID: 32018085 DOI: 10.1016/j.biortech.2020.122859] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/24/2019] [Revised: 01/19/2020] [Accepted: 01/21/2020] [Indexed: 06/10/2023]
Abstract
This paper investigated the effects of citric acid (CA) on extracellular polymer destruction and cell lysis in sludge at different initial pH by measuring capillary suction time (CST), extracellular polymeric substances (EPS) and intracellular bound water. The results indicated that under CA concentration at 0.05 g/g suspended solids (SS) and initial pH 4, the CST value decreased from 175.5 s to 112.3 s, slime extracellular polymeric substances (S-EPS) and loosely bound EPS (LB-EPS) content respectively to increase from 4.92 to 41.43, 2.27 to 5.49 mg/g volatile suspended solids (Vss), while tightly bound EPS (TB-EPS) content to decrease from 12.35 to 5.01 mg/g (Vss), which suggested CA could disrupt outer EPS effectively. Intracellular bound water content decreased from 1.23 g/g to 0.41 g/g dry solid (DS). As a result, CA could release intracellular bound water effectively, thereby improving sludge dewatering degree.
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Affiliation(s)
- Xuewei Wu
- College of Environmental Science and Engineering, Hunan University, Changsha 410082, PR China; Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Changsha 410082, PR China.
| | - Xiaoming Li
- College of Environmental Science and Engineering, Hunan University, Changsha 410082, PR China; Key Laboratory of Environmental 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 Environmental 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 Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Changsha 410082, PR China
| | - Ziletao Tao
- College of Environmental Science and Engineering, Hunan University, Changsha 410082, PR China; Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Changsha 410082, PR China
| | - Xiaoding Huang
- College of Environmental Science and Engineering, Hunan University, Changsha 410082, PR China; Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Changsha 410082, PR China
| | - You Wu
- College of Environmental Science and Engineering, Hunan University, Changsha 410082, PR China; Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Changsha 410082, PR China
| | - Lingjuan Tao
- College of Environmental Science and Engineering, Hunan University, Changsha 410082, PR China; Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Changsha 410082, PR China
| | - Zhoujie Pi
- College of Environmental Science and Engineering, Hunan University, Changsha 410082, PR China; Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Changsha 410082, PR China
| | - Zhuo Chen
- College of Environmental Science and Engineering, Hunan University, Changsha 410082, PR China; Key Laboratory of Environmental 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 Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Changsha 410082, PR China
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