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Qi Y, Cao W, Zhang Y, Qu R, Mahmoud RK, Abukhadra MR, Huo Z, Zhu F. Efficient degradation of benzalkonium chloride (BAC) by zero-valent iron activated persulfate: Kinetics, reaction mechanisms, theoretical calculations and toxicity evolution. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2024; 360:124687. [PMID: 39116919 DOI: 10.1016/j.envpol.2024.124687] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/14/2024] [Revised: 07/22/2024] [Accepted: 08/02/2024] [Indexed: 08/10/2024]
Abstract
The present study systematically investigated the elimination of benzalkonium chloride (BAC) in the zero valent iron activated persulfate (Fe0/PS) system. The influence of operational parameters, including PS concentration, Fe0 dosage and pH, were investigated through a series of kinetic experiments. When the Fe0 dosage was 5.0 mM, the initial ratio of [PS]:[BAC] was 10:1, the degradation efficiency could achieve 91.7% at pH 7.0 within 60 min. Common inorganic anions and humic acid did not significantly affect BAC degradation, implying that Fe0/PS system had a potential application prospect in the actual wastewater remediation. Based on the electron paramagnetic resonance test and quenching experiments, the BAC degradation was found to be contributed by •OH, SO4•- and Fe(IV). A total of 23 intermediates were identified by the liquid chromatography-mass spectrometry, and the degradation pathways were proposed accordingly, including dealkylation and demethylation, hydroxylation, sulfate substitution and benzyl C-N cleavage reactions. Density functional theory based calculations were conducted to realize the rationality of the proposed reaction mechanisms. The toxicity of transformation products was predicted by ECOSAR program. This work demonstrated the possibility of BAC removal in hospital and municipal wastewater by Fe0/PS treatment, and also provides a safe choice for deep treatment of quaternary ammonium salt wastewater.
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Affiliation(s)
- Yumeng Qi
- State Key Laboratory of Pollution Control and Resources Reuse, School of the Environment, Nanjing University, Jiangsu Nanjing 210023, PR China
| | - Wenqian Cao
- State Key Laboratory of Pollution Control and Resources Reuse, School of the Environment, Nanjing University, Jiangsu Nanjing 210023, PR China
| | - Ying Zhang
- State Key Laboratory of Pollution Control and Resources Reuse, School of the Environment, Nanjing University, Jiangsu Nanjing 210023, PR China
| | - Ruijuan Qu
- State Key Laboratory of Pollution Control and Resources Reuse, School of the Environment, Nanjing University, Jiangsu Nanjing 210023, PR China
| | - Rehab Khaled Mahmoud
- Department of Chemistry, Faculty of science, Beni Suef University, Beni Suef city, Egypt
| | - Mostafa R Abukhadra
- Materials Technologies and their applications Lab, Geology Department, Faculty of Science, Beni Suef University, Beni Suef city, Egypt
| | - Zongli Huo
- Jiangsu Provincial Center for Disease Control and Prevention, NO.172 Jiangsu Road, Jiangsu Nanjing 210023, PR China
| | - Feng Zhu
- Jiangsu Provincial Center for Disease Control and Prevention, NO.172 Jiangsu Road, Jiangsu Nanjing 210023, PR China.
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Wang Z, Lü C, Wang Y, Gomes RL, Clarke CJ, Gomes HI. Zero-valent iron (ZVI) facilitated in-situ selenium (Se) immobilization and its recovery by magnetic separation: Mechanisms and implications for microbial ecology. JOURNAL OF HAZARDOUS MATERIALS 2024; 473:134591. [PMID: 38761763 DOI: 10.1016/j.jhazmat.2024.134591] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/28/2024] [Revised: 05/03/2024] [Accepted: 05/10/2024] [Indexed: 05/20/2024]
Abstract
Selenium (Se(VI)) is environmentally toxic. One of the most popular reducing agents for Se(VI) remediation is zero-valent iron (ZVI). However, most ZVI studies were carried out in water matrices, and the recovery of reduced Se has not been investigated. A water-sediment system constructed using natural sediment was employed here to study in-situ Se remediation and recovery. A combined effect of ZVI and unacclimated microorganisms from natural sediment was found in Se(VI) removal in the water phase with a removal efficiency of 92.7 ± 1.1% within 7 d when 10 mg L-1 Se(VI) was present. Soluble Se(VI) was removed from the water and precipitated to the sediment phase (74.8 ± 0.1%), which was enhanced by the addition of ZVI (83.3 ± 0.3%). The recovery proportion of the immobilized Se was 34.2 ± 0.1% and 92.5 ± 0.2% through wet and dry magnetic separation with 1 g L-1 ZVI added, respectively. The 16 s rRNA sequencing revealed the variations in the microbial communities in response to ZVI and Se, which the magnetic separation could potentially mitigate in the long term. This study provides a novel technique to achieve in-situ Se remediation and recovery by combining ZVI reduction and magnetic separation.
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Affiliation(s)
- Zhongli Wang
- Ministry of Education Key Laboratory of Ecology and Resources Use of the Mongolian Plateau, School of Ecology and Environment, Inner Mongolia University, Hohhot 010021, China; Food Water Waste Research Group, Faculty of Engineering, University of Nottingham, University Park, Nottingham NG7 2RD, United Kingdom.
| | - Changwei Lü
- Ministry of Education Key Laboratory of Ecology and Resources Use of the Mongolian Plateau, School of Ecology and Environment, Inner Mongolia University, Hohhot 010021, China
| | - Yanming Wang
- Food Water Waste Research Group, Faculty of Engineering, University of Nottingham, University Park, Nottingham NG7 2RD, United Kingdom
| | - Rachel L Gomes
- Food Water Waste Research Group, Faculty of Engineering, University of Nottingham, University Park, Nottingham NG7 2RD, United Kingdom
| | - Coby J Clarke
- Glaxo Smith Kline Carbon Neutral Laboratory for Sustainable Chemistry, University of Nottingham, Nottingham NG7 2GA, United Kingdom
| | - Helena I Gomes
- Food Water Waste Research Group, Faculty of Engineering, University of Nottingham, University Park, Nottingham NG7 2RD, United Kingdom
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Liu Z, Luo F, He L, Wang S, Wu Y, Chen Z. Physical conditioning methods for sludge deep dewatering: A critical review. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2024; 360:121207. [PMID: 38788408 DOI: 10.1016/j.jenvman.2024.121207] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/22/2024] [Revised: 04/17/2024] [Accepted: 05/18/2024] [Indexed: 05/26/2024]
Abstract
Sludge is an inevitable waste product of sewage treatment with a high water content and large volume, it poses a significant threat of secondary pollution to both water and the atmosphere without proper disposal. In this regard, dewatering has emerged as an attractive method in sludge treatment, as it can reduce the sludge volume, enhance its transportability and calorific value, and even decrease the production of landfill leachate. In recent years, physical conditioning methods including non-chemical conditioners or energy input alone, have been extensively researched for their potential to enhance sludge dewatering efficiency, such as thermal treatment, freeze-thaw, microwave, ultrasonic, skeleton builders addition, and electro-dewatering, as well as combined methods. The main objective of this paper is to comprehensively evaluate the dewatering capacity of various physical conditioning methods, and identify key factors affecting sludge dewatering efficiency. In addition, future research anticipated directions and outlooks are proposed. This work is expected to provide valuable insights for developing efficient, eco-friendly, and low-energy consumption techniques for deep sludge dewatering.
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Affiliation(s)
- Zhuo Liu
- Key Laboratory of Material Chemistry for Energy Conversion and Storage, Ministry of Education, Hubei Key Laboratory of Material Chemistry and Service Failure, School of Chemistry and Chemical Engineering, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Fang Luo
- Key Laboratory of Material Chemistry for Energy Conversion and Storage, Ministry of Education, Hubei Key Laboratory of Material Chemistry and Service Failure, School of Chemistry and Chemical Engineering, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Lingzhi He
- Key Laboratory of Material Chemistry for Energy Conversion and Storage, Ministry of Education, Hubei Key Laboratory of Material Chemistry and Service Failure, School of Chemistry and Chemical Engineering, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Siqi Wang
- Key Laboratory of Material Chemistry for Energy Conversion and Storage, Ministry of Education, Hubei Key Laboratory of Material Chemistry and Service Failure, School of Chemistry and Chemical Engineering, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Yi Wu
- Key Laboratory of Material Chemistry for Energy Conversion and Storage, Ministry of Education, Hubei Key Laboratory of Material Chemistry and Service Failure, School of Chemistry and Chemical Engineering, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Zhuqi Chen
- Key Laboratory of Material Chemistry for Energy Conversion and Storage, Ministry of Education, Hubei Key Laboratory of Material Chemistry and Service Failure, School of Chemistry and Chemical Engineering, Huazhong University of Science and Technology, Wuhan 430074, China.
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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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Yu B, Zhang Y, Wu H, Yan W, Meng Y, Hu C, Liu Z, Ding J, Zhang H. Advanced oxidation processes for synchronizing harmful microcystis blooms control with algal metabolites removal: From the laboratory to practical applications. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 906:167650. [PMID: 37806585 DOI: 10.1016/j.scitotenv.2023.167650] [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: 07/30/2023] [Revised: 10/05/2023] [Accepted: 10/05/2023] [Indexed: 10/10/2023]
Abstract
Harmful algal blooms (HABs) in freshwater systems have become a global epidemic, leading to a series of problems related to cyanobacterial outbreaks and toxicity. Studies are needed to improve the technology used for the simultaneous removal of harmful cyanobacteria and algal metabolites. In this review, widely reported advanced oxidation processes (AOPs) strategies for removing major species Microcystis aeruginosa (M. aeruginosa) and microcystins (MCs) were screened through bibliometrics, such as photocatalysis, activated persulfate, H2O2, Ozone oxidation, ultrasonic oxidation, and electrochemical oxidation, etc. AOPs generate kinds of reactive oxygen species (ROS) to inactivate cyanobacteria and degrade cyanotoxins. A series of responses occurs in algal cells to resist the damaging effects of ROS generated by AOPs. Specifically, we reviewed laboratory research, mechanisms, practical applications, and challenges of HABs treatments in AOPs. Problems common to these technologies include the impact of algal response and metabolites, and environmental factors. This information provides guidance for future research on the removal of harmful cyanobacteria and treatment of algal metabolites using AOPs.
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Affiliation(s)
- Bingzhi Yu
- School of Life and Environmental Sciences, Hangzhou Normal University, 311121 Hangzhou, Zhejiang, China
| | - Yinan Zhang
- School of Life and Environmental Sciences, Hangzhou Normal University, 311121 Hangzhou, Zhejiang, China
| | - Huazhen Wu
- Hangzhou Huanke Environmental Consulting Co. LTD, 310010 Hangzhou, Zhejiang, China
| | - Wen Yan
- School of Life and Environmental Sciences, Hangzhou Normal University, 311121 Hangzhou, Zhejiang, China
| | - Yunjuan Meng
- School of Life and Environmental Sciences, Hangzhou Normal University, 311121 Hangzhou, Zhejiang, China
| | - Chao Hu
- School of Life and Environmental Sciences, Hangzhou Normal University, 311121 Hangzhou, Zhejiang, China
| | - Zhiquan Liu
- School of Engineering, Hangzhou Normal University, 310018 Hangzhou, Zhejiang, China; Zhejiang Provincial Key Laboratory of Urban Wetlands and Regional Change, 311121 Hangzhou, Zhejiang, China
| | - Jiafeng Ding
- School of Engineering, Hangzhou Normal University, 310018 Hangzhou, Zhejiang, China; Zhejiang Provincial Key Laboratory of Urban Wetlands and Regional Change, 311121 Hangzhou, Zhejiang, China.
| | - Hangjun Zhang
- School of Engineering, Hangzhou Normal University, 310018 Hangzhou, Zhejiang, China; Zhejiang Provincial Key Laboratory of Urban Wetlands and Regional Change, 311121 Hangzhou, Zhejiang, China
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Cui H, Zhan W, Ji X, Jiang M, Wu X, Huang M, Huang C, Ma S. Removal of sulfonamide antibiotics by a sonocatalytic Fenton-like reaction: Efficiency and mechanisms. ENVIRONMENTAL RESEARCH 2023; 239:117408. [PMID: 37838205 DOI: 10.1016/j.envres.2023.117408] [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: 09/05/2023] [Revised: 10/07/2023] [Accepted: 10/11/2023] [Indexed: 10/16/2023]
Abstract
With the widespread use of sulfonamide antibiotics (SAs), SAs are detected as residues in aquatic environments, posing a serious threat to human life and safety. Because of their high water solubility, fast transmission rate, and strong antibacterial properties, the safe disposal of SAs has become a key constraint for water quality assurance. Therefore, an ultrasound (US)-assisted zero-valent iron (ZVI)/persulfate (PS) system was proposed to explore the rapid and effective degradation of SAs. Comparative experiments were performed to study the removal of sulfadiazine (SDZ) by US, ZVI, PS, US/ZVI, US/PS, ZVI/PS, and US-ZVI/PS systems, respectively. Experimental results indicated that the highest removal efficiency of SDZ was ahieved in US-ZVI/PS system (97.4%), which were 2-44 times higher than that in other systems. Furthermore, the degradation efficiency of five typical SAs was achieved over 95%, demonstrating the effectiveness of the US ZVI/PS system for SAs removal. Also, quantum chemical computations for potential reactive sites of SAs and intermediate product detection by HPLC‒MS/MS were performed. The radical attack on active sites of SAs, such as N atom (number 7), was the main reason for SAs removal in US-ZVI/PS system. Besides, the common degradation pathways of six typical SAs were defined as S-N bond cleavage, C-N bond cleavage, benzene ring hydroxylation, aniline oxidation, and R substituent oxidation. Interestingly, the unique pathway of "SO2 group extraction" was observed in the degradation of six-membered ring SAs. Therefore, the US-ZVI/PS system is a promising and cost-effective method for the removal of SAs and other refractory pollutants.
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Affiliation(s)
- Hao Cui
- Guangzhou Institute of Building Science Group Co., Ltd., Guangzhou, 510440, China; South China University of Technology, Guangzhou, 510641, China
| | - Wei Zhan
- State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, Harbin, 150090, China.
| | - Xuan Ji
- Guangzhou Institute of Building Science Group Co., Ltd., Guangzhou, 510440, China
| | - Mingye Jiang
- Guangzhou Institute of Building Science Group Co., Ltd., Guangzhou, 510440, China
| | - Xiaoting Wu
- Guangzhou Institute of Building Science Group Co., Ltd., Guangzhou, 510440, China
| | - Minru Huang
- Guangzhou Institute of Building Science Group Co., Ltd., Guangzhou, 510440, China
| | - Chenhui Huang
- School of Ecological Environment, Guangdong Industry Polytechnic, Guangzhou, 510300, China
| | - Shanshan Ma
- School of Ecological Environment, Guangdong Industry Polytechnic, Guangzhou, 510300, China.
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Bi W, Chen M, Hu C, Sun H, Xu S, Jiang J, Wang L, Li X, Deng J. Insight into sludge dewatering by periodate driven directly with Fe(Ⅱ): Extracellular polymeric substances solubilization and mineralization. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2023; 344:118450. [PMID: 37413734 DOI: 10.1016/j.jenvman.2023.118450] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/10/2023] [Revised: 05/25/2023] [Accepted: 06/16/2023] [Indexed: 07/08/2023]
Abstract
The production of waste activated sludge is expanding in tandem with the significant growth in the global population. It is important to explore sludge pretreatment technology to achieve sludge reduction. In this study, deep sludge dewatering was achieved by using Fe2+-catalyzed periodate (Fe2+/PI) conditioning. The result showed that capillary suction time was reduced by 48.27% under the optimum Fe2+ and PI dosages. ·OH, FeⅣ, O2·-, 1O2, and IO3· generated from the reaction between Fe2+ and PI, while ·OH (49.79%) and FeⅣ (47.76%) contributed significantly to sludge dewatering. Investigations of the mechanism revealed that the synergistic action of radical species oxidation and iron species flocculation in Fe2+/PI conditioning led to the mineralization and aggregation of hydrophilic substances in extracellular polymeric substances. The hydrophobic groups on the protein surface were more exposed to soluble extracellular polymeric substances and reduced protein-water interaction. The variations in zeta potential and particle size also verified the presence of a synergistic effect of oxidation and flocculation. The morphology observations revealed that the increased frictional forces generated when water flowed over the raw sludge (RS) surface prevented the rapid passage of internal water. In addition, the hydrophobic and electrostatic interactions in the sludge samples were essential influences that promoted flocculation and sedimentation of the sludge. This research aids engineers by providing a new option to better optimize sludge management while also deepening understanding of the Fe2+/PI conditioning involved in sludge dewatering.
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Affiliation(s)
- Weiwei Bi
- College of Civil Engineering, Zhejiang University of Technology, Hangzhou, 310023, China; Zhejiang Key Laboratory of Civil Engineering Structures & Disaster Prevention and Mitigation Technology, Hangzhou, 310023, China
| | - Minjie Chen
- College of Civil Engineering, Zhejiang University of Technology, Hangzhou, 310023, China
| | - Chenkai Hu
- College of Civil Engineering, Zhejiang University of Technology, Hangzhou, 310023, China
| | - Honglei Sun
- College of Civil Engineering, Zhejiang University of Technology, Hangzhou, 310023, China; Zhejiang Key Laboratory of Civil Engineering Structures & Disaster Prevention and Mitigation Technology, Hangzhou, 310023, China
| | - Shanlin Xu
- College of Civil Engineering, Zhejiang University of Technology, Hangzhou, 310023, China; Zhejiang Key Laboratory of Civil Engineering Structures & Disaster Prevention and Mitigation Technology, Hangzhou, 310023, China
| | - Jiahong Jiang
- College of Civil Engineering, Zhejiang University of Technology, Hangzhou, 310023, China
| | - Lei Wang
- College of Civil Engineering, Zhejiang University of Technology, Hangzhou, 310023, China
| | - Xueyan Li
- School of Environmental Science and Engineering, Suzhou University of Science and Technology, Suzhou, 215009, China
| | - Jing Deng
- College of Civil Engineering, Zhejiang University of Technology, Hangzhou, 310023, China; Zhejiang Key Laboratory of Civil Engineering Structures & Disaster Prevention and Mitigation Technology, Hangzhou, 310023, China.
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Luo J, Yi Y, Fang Z. Nitrogen-rich magnetic biochar prepared by urea was used as an efficient catalyst to activate persulfate to degrade organic pollutants. CHEMOSPHERE 2023; 339:139614. [PMID: 37482309 DOI: 10.1016/j.chemosphere.2023.139614] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/29/2023] [Revised: 07/05/2023] [Accepted: 07/21/2023] [Indexed: 07/25/2023]
Abstract
In order to fully exploit the potential of magnetic biochar-based persulfate (PS) systems, N was utilized to modify the magnetic biochar-based catalysts through impregnation-pyrolysis method. A typical antifungal drug, metronidazole (MNZ), is selected as the target pollutant to score the reactivity of as-synthetic nitrogen-rich magnetic biochar (NMBC) catalysts. In the modified system, 99.6% of MNZ was removed, 13.6 times of that in the unmodified system. Active radical verification experiments showed that 1O2 was the key active radical. Various characterization showed that the nitrogen-rich significantly improved the persistent free radical, defect degree, content of oxygen-containing groups, electrochemical conductivity and other catalytic activity related properties. Physicochemical characterization, Fe(II) semi-quantitative analysis and masking experiments confirmed that the doping of magnetic biochar with nitrogen increased its Fe(II) content (23.79 mg/g), approximately 2.6 times higher than that of pristine magnetic biochar. Moreover, N induces strong electron accretion of Fe atom through coordination bond, which leads to the increase of electron density on the Fe atom, which increases the content of Fe (II) in the material, thus improving the ability of the material to activate PS to generate 1O2, and promoting the degradation reaction of MNZ. This paper provides a method to improve the activation performance of magnetic biochar.
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Affiliation(s)
- Jiayi Luo
- School of Environment, South China Normal University, Guangzhou, 510006, China; Guangdong Technology Research Center for Ecological Management and Remediation of Water System, Guangzhou, 510006, China; SCNU Qingyuan Institute of Science and Technology Innovation Co., Ltd., Qingyuan, 511517, China
| | - Yunqiang Yi
- School of Environment, South China Normal University, Guangzhou, 510006, China; Guangdong Technology Research Center for Ecological Management and Remediation of Water System, Guangzhou, 510006, China; SCNU Qingyuan Institute of Science and Technology Innovation Co., Ltd., Qingyuan, 511517, China
| | - Zhanqiang Fang
- School of Environment, South China Normal University, Guangzhou, 510006, China; Guangdong Technology Research Center for Ecological Management and Remediation of Water System, Guangzhou, 510006, China; SCNU Qingyuan Institute of Science and Technology Innovation Co., Ltd., Qingyuan, 511517, China.
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9
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Wan P, Liu Y, Zhang Q, Jiang L, Chen H, Lv W. Enhanced degradation of extracellular polymeric substances by yeast in activated sludge to achieve sludge reduction. BIORESOURCE TECHNOLOGY 2023; 377:128915. [PMID: 36934907 DOI: 10.1016/j.biortech.2023.128915] [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: 02/01/2023] [Revised: 03/10/2023] [Accepted: 03/15/2023] [Indexed: 06/18/2023]
Abstract
Candida Tropicalis was used to improve the dewaterability of activated sludge (AS) and reduce its biomass by degrading EPS in AS. The protein, polysaccharide, and hydrophilic amino acids in EPS decreased by 54.50, 29.20, and 61.01%, respectively. Meanwhile, molecular weight distribution indicated that yeast degraded macromolecular organics into small molecular ones. The direct addition of yeast to AS was more conducive to EPS degradation. With the addition of 0.75 g/L of wet yeast cells and 24 h of aeration enhanced the dewaterability of AS. The CST and MLSS decreased by 24.44 and 10.51%, respectively. After 30 days of operation of lab-scale continuous SBRs, the CST and MLSS of AS were reduced by 6.37 ± 2.01 and 3.57 ± 0.52%, respectively. FTIR spectroscopy results showed that some hydrophilic functional groups were reduced. This study provides a new approach for the in-situ reduction of AS in wastewater treatment plant.
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Affiliation(s)
- Pengfei Wan
- School of Civil & Environmental Engineering and Geography Science, Ningbo University, Ningbo 315211, China
| | - Ying Liu
- School of Civil & Environmental Engineering and Geography Science, Ningbo University, Ningbo 315211, China
| | - Quandi Zhang
- School of Civil & Environmental Engineering and Geography Science, Ningbo University, Ningbo 315211, China
| | - Li Jiang
- School of Civil & Environmental Engineering and Geography Science, Ningbo University, Ningbo 315211, China
| | - Heping Chen
- School of Civil & Environmental Engineering and Geography Science, Ningbo University, Ningbo 315211, China
| | - Wenzhou Lv
- School of Civil & Environmental Engineering and Geography Science, Ningbo University, Ningbo 315211, China.
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