1
|
Lin Q, Xi S, Cheng B, Jiang J, Zan F, Tang Y, Li Y, Khanal SK, Wang Z, Chen G, Guo G. Electrogenerated singlet oxygen and reactive chlorine species enhancing volatile fatty acids production from co-fermentation of waste activated sludge and food waste: The key role of metal oxide coated electrodes. WATER RESEARCH 2024; 260:121953. [PMID: 38901317 DOI: 10.1016/j.watres.2024.121953] [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: 02/24/2024] [Revised: 06/06/2024] [Accepted: 06/15/2024] [Indexed: 06/22/2024]
Abstract
Electrochemical pretreatment (EPT) has shown to be superior in improving acidogenic co-fermentation (Co-AF) of waste activated sludge (WAS) and food waste (FW) for volatile fatty acids (VFAs). However, the influence of EPT electrode materials on the production of electrogenerated oxidants (such as singlet oxygen (1O2) and reactive chlorine species (RCS)), as well as their effects on properties of electrodes, the microbial community structure and functional enzymes remain unclear. Therefore, this study investigated the effects of various metal oxide coated electrodes (i.e., Ti/PbO2, Ti/Ta2O5-IrO2, Ti/SnO2-RuO2, and Ti/IrO2-RuO2) on EPT and subsequent Co-AF of WAS-FW. The results showed that EPT with Ti/PbO2, Ti/Ta2O5-IrO2, Ti/SnO2-RuO2 and Ti/IrO2-RuO2 electrodes generated 165.3-848.2 mg Cl2/L of RCS and 5.643 × 1011-3.311 × 1012 spins/mm3 of 1O2, which significantly enhanced the solubilization and biodegradability of WAS-FW by 106.4 %-233.6 % and 177.3 %-481.8 %, respectively. Especially with Ti/Ta2O5-IrO2 as the electrode material, an appropriate residual RCS (2.0-10.4 mg Cl2/L) remained in Co-AF step, resulted in hydrolytic and acidogenic bacteria (e.g., Prevotella_7, accounting for 78.9 %) gradually become dominant rather than methanogens (e.g., Methanolinea and Methanothrix) due to their different tolerance to residual RCS. Meanwhile, the functional gene abundances of hydrolytic and acidogenic enzymes increased, while the methanogenic enzymes deceased. Consequently, this reactor produced the highest VFAs up to 545.5 ± 36.0 mg COD/g VS, which was 101.8 % higher than that of the Control (without EPT). Finally, the economic analysis and confirmatory experiments further proved the benefits of WAS-FW Co-AF with EPT.
Collapse
Affiliation(s)
- Qingshan Lin
- Hubei Key Laboratory of Multi-media Pollution Cooperative Control in Yangtze Basin, School of Environmental Science and Engineering, Huazhong University of Science and Technology (HUST), Wuhan, Hubei 430074, China; Chongqing Key Laboratory for Resource Utilization of Heavy Metal Wastewater, Chongqing University of Arts and Sciences, Yongchuan 402160, PR China
| | - Shihao Xi
- Hubei Key Laboratory of Multi-media Pollution Cooperative Control in Yangtze Basin, School of Environmental Science and Engineering, Huazhong University of Science and Technology (HUST), Wuhan, Hubei 430074, China
| | - Boyi Cheng
- Hubei Key Laboratory of Multi-media Pollution Cooperative Control in Yangtze Basin, School of Environmental Science and Engineering, Huazhong University of Science and Technology (HUST), Wuhan, Hubei 430074, China
| | - Jinqi Jiang
- Hubei Key Laboratory of Multi-media Pollution Cooperative Control in Yangtze Basin, School of Environmental Science and Engineering, Huazhong University of Science and Technology (HUST), Wuhan, Hubei 430074, China
| | - Feixiang Zan
- Hubei Key Laboratory of Multi-media Pollution Cooperative Control in Yangtze Basin, School of Environmental Science and Engineering, Huazhong University of Science and Technology (HUST), Wuhan, Hubei 430074, China
| | - Yuanzhe Tang
- Chongqing Key Laboratory for Resource Utilization of Heavy Metal Wastewater, Chongqing University of Arts and Sciences, Yongchuan 402160, PR China
| | - Yeqing Li
- College of New Energy and Materials, China University of Petroleum Beijing (CUPB), Beijing 102249, China
| | - Samir Kumar Khanal
- Department of Molecular Biosciences and Bioengineering (MBBE), University of Hawaii at Mānoa, Honolulu, USA
| | - Zongping Wang
- Hubei Key Laboratory of Multi-media Pollution Cooperative Control in Yangtze Basin, School of Environmental Science and Engineering, Huazhong University of Science and Technology (HUST), Wuhan, Hubei 430074, China
| | - Guanghao Chen
- Department of Civil and Environmental Engineering, The Hong Kong University of Science and Technology, Hong Kong, China
| | - Gang Guo
- Hubei Key Laboratory of Multi-media Pollution Cooperative Control in Yangtze Basin, School of Environmental Science and Engineering, Huazhong University of Science and Technology (HUST), Wuhan, Hubei 430074, China.
| |
Collapse
|
2
|
Fu Q, Li C, Liu Z, Ma X, Xu Y, Wang Y, Liu X, Wang D. The Impact of Bisphenol A on the Anaerobic Sulfur Transformation: Promoting Sulfur Flow and Toxic H 2S Production. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2024; 58:8043-8052. [PMID: 38648493 DOI: 10.1021/acs.est.4c00612] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/25/2024]
Abstract
Bisphenol A (BPA), as a typical leachable additive from microplastics and one of the most productive bulk chemicals, is widely distributed in sediments, sewers, and wastewater treatment plants, where active sulfur cycling takes place. However, the effect of BPA on sulfur transformation, particularly toxic H2S production, has been previously overlooked. This work found that BPA at environmentally relevant levels (i.e., 50-200 mg/kg total suspended solids, TSS) promoted the release of soluble sulfur compounds and increased H2S gas production by 14.3-31.9%. The tryptophan-like proteins of microbe extracellular polymeric substances (EPSs) can spontaneously adsorb BPA, which is an enthalpy-driven reaction (ΔH = -513.5 kJ mol-1, ΔS = -1.60 kJ mol-1K -1, and ΔG = -19.52 kJ mol-1 at 35 °C). This binding changed the composition and structure of EPSs, which improved the direct electron transfer capacity of EPSs, thereby promoting the bioprocesses of organic sulfur hydrolysis and sulfate reduction. In addition, BPA presence enriched the functional microbes (e.g., Desulfovibrio and Desulfuromonas) responsible for organic sulfur mineralization and inorganic sulfate reduction and increased the abundance of related genes involved in ATP-binding cassette transporters and sulfur metabolism (e.g., Sat and AspB), which promoted anaerobic sulfur transformation. This work deepens our understanding of the interaction between BPA and sulfur transformation occurring in anaerobic environments.
Collapse
Affiliation(s)
- Qizi Fu
- College of Environmental Science and Engineering and Key Laboratory of Environmental Biology and Pollution Control (Ministry of Education), Hunan University, Changsha 410082, PR China
| | - Chenxi Li
- College of Environmental Science and Engineering and Key Laboratory of Environmental Biology and Pollution Control (Ministry of Education), Hunan University, Changsha 410082, PR China
| | - Zirui Liu
- College of Environmental Science and Engineering and Key Laboratory of Environmental Biology and Pollution Control (Ministry of Education), Hunan University, Changsha 410082, PR China
| | - Xingyu Ma
- College of Environmental Science and Engineering and Key Laboratory of Environmental Biology and Pollution Control (Ministry of Education), Hunan University, Changsha 410082, PR China
| | - Yunhao Xu
- College of Environmental Science and Engineering and Key Laboratory of Environmental Biology and Pollution Control (Ministry of Education), Hunan University, Changsha 410082, PR China
| | - Yan Wang
- College of Environmental Science and Engineering and Key Laboratory of Environmental Biology and Pollution Control (Ministry of Education), Hunan University, Changsha 410082, PR China
| | - Xuran Liu
- College of Environmental Science and Engineering and Key Laboratory of Environmental Biology and Pollution Control (Ministry of Education), Hunan University, Changsha 410082, PR China
| | - Dongbo Wang
- College of Environmental Science and Engineering and Key Laboratory of Environmental Biology and Pollution Control (Ministry of Education), Hunan University, Changsha 410082, PR China
| |
Collapse
|
3
|
Li X, Fu Q, Wang W, Liu X, He D, Jiang X, Yang Q, Wang D. Surfactant enhances anaerobic fermentative hydrogen sulfide production: Changes in sulfur-containing organics structure and microbial community. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 880:163025. [PMID: 36966824 DOI: 10.1016/j.scitotenv.2023.163025] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/07/2023] [Revised: 03/19/2023] [Accepted: 03/19/2023] [Indexed: 05/27/2023]
Abstract
The presence of surfactants in waste activated sludge (WAS) system is generally regarded as beneficial to sludge treatment such as enhancing sludge dewatering and improving value-added fermentation products generation. However, in this study, it was firstly found that sodium dodecylbenzene sulfonate (SDBS, a typical surfactant) obviously increased toxic hydrogen sulfide (H2S) gas production from WAS anaerobic fermentation at environmentally relevant concentrations. Experimental results showed that H2S production from WAS significantly increased from 53.24 × 10-3 to 111.25 × 10-3 mg/g volatile suspended solids (VSS) when SDBS level increased from 0 to 30 mg/g total suspended solid (TSS). It was found that SDBS presence destroyed WAS structure and enhanced sulfur containing organics release. SDBS reduced the proportion of α-helix structure, damaged disulfide bridges and protein conformation, and effectively destroyed protein structure. SDBS promoted sulfur containing organics degradation and provided more readily hydrolyzed micro-molecule organics for sulfide production. Microbial analysis showed that SDBS addition enhanced the abundance of functional genes encoding protease, ATP-binding cassette transporters, and amino acids lyase, enhanced the activities and abundance of hydrolytic microbes, thus increased sulfide production from the hydrolysis of sulfur containing organics. Compared with the control, 30 mg/g TSS SDBS increased organic sulfurs hydrolysis and amino acids degradation by 47.1 % and 63.5 %, respectively. Key genes analysis further showed that SDBS addition promoted sulfate transport system and dissimilatory sulfate reduction. SDBS presence also lowered fermentation pH, promoted the chemical equilibrium transformation of sulfide, thus increased H2S gas release.
Collapse
Affiliation(s)
- Xuemei Li
- College of Environmental Science and Engineering and Key Laboratory of Environmental Biology and Pollution Control (Ministry of Education), Hunan University, Changsha 410082, PR China
| | - Qizi Fu
- College of Environmental Science and Engineering and Key Laboratory of Environmental Biology and Pollution Control (Ministry of Education), Hunan University, Changsha 410082, PR China.
| | - Wenming Wang
- Hunan Pilot Yanghu Reclaimed Water Co. Ltd., Changsha 410082, PR China.
| | - Xuran Liu
- College of Environmental Science and Engineering and Key Laboratory of Environmental Biology and Pollution Control (Ministry of Education), Hunan University, Changsha 410082, PR China
| | - Dandan He
- College of Environmental Science and Engineering and Key Laboratory of Environmental Biology and Pollution Control (Ministry of Education), Hunan University, Changsha 410082, PR China
| | - Xiaomei Jiang
- Hunan Pilot Yanghu Reclaimed Water Co. Ltd., Changsha 410082, PR China
| | - Qiliang Yang
- Hunan Pilot Yanghu Reclaimed Water Co. Ltd., Changsha 410082, PR China
| | - Dongbo Wang
- College of Environmental Science and Engineering and Key Laboratory of Environmental Biology and Pollution Control (Ministry of Education), Hunan University, Changsha 410082, PR China.
| |
Collapse
|
4
|
Fu Q, Long S, Xu Y, Wang Y, Yang B, He D, Li X, Liu X, Lu Q, Wang D. Revealing an unrecognized role of free ammonia in sulfur transformation during sludge anaerobic treatment. JOURNAL OF HAZARDOUS MATERIALS 2023; 452:131305. [PMID: 37002999 DOI: 10.1016/j.jhazmat.2023.131305] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/08/2023] [Revised: 03/03/2023] [Accepted: 03/25/2023] [Indexed: 05/03/2023]
Abstract
Free ammonia (FA), the unionized form of ammonium, is presented in anaerobic fermentation of waste activated sludge (WAS) at high levels. However, its potential role in sulfur transformation, especially H2S production, during WAS anaerobic fermentation process was unrecognized previously. This work aims to unveil how FA affects anaerobic sulfur transformation in WAS anaerobic fermentation. It was found that FA significantly inhibited H2S production. With an increase of FA from 0.04 to 159 mg/L, H2S production reduced by 69.9%. FA firstly attacked tyrosine-like proteins and aromatic-like proteins in sludge EPSs, with CO groups being responded first, which decreased the percentage of α-helix/(β-sheet + random coil) and destroyed hydrogen bonding networks. Cell membrane potential and physiological status analysis showed that FA destroyed membrane integrity and increased the ratio of apoptotic and necrotic cells. These destroyed sludge EPSs structure and caused cell lysis, thus strongly inhibited the activities of hydrolytic microorganisms and sulfate reducing bacteria. Microbial analysis showed that FA reduced the abundance of functional microbes (e.g., Desulfobulbus and Desulfovibrio) and genes (e.g., MPST, CysP, and CysN) involved in organic sulfur hydrolysis and inorganic sulfate reduction. These findings unveil an actually existed but previously overlooked contributor to H2S inhibition in WAS anaerobic fermentation.
Collapse
Affiliation(s)
- Qizi Fu
- College of Environmental Science and Engineering and Key Laboratory of Environmental Biology and Pollution Control (Ministry of Education), Hunan University, Changsha 410082, PR China
| | - Sha Long
- College of Environmental Science and Engineering and Key Laboratory of Environmental Biology and Pollution Control (Ministry of Education), Hunan University, Changsha 410082, PR China
| | - Yunhao Xu
- College of Environmental Science and Engineering and Key Laboratory of Environmental Biology and Pollution Control (Ministry of Education), Hunan University, Changsha 410082, PR China
| | - Yan Wang
- College of Environmental Science and Engineering and Key Laboratory of Environmental Biology and Pollution Control (Ministry of Education), Hunan University, Changsha 410082, PR China
| | - Bentao Yang
- Zhongye Changtian International Engineering Co., Ltd., Changsha 410205, PR China
| | - Dandan He
- College of Environmental Science and Engineering and Key Laboratory of Environmental Biology and Pollution Control (Ministry of Education), Hunan University, Changsha 410082, PR China
| | - Xuemei Li
- College of Environmental Science and Engineering and Key Laboratory of Environmental Biology and Pollution Control (Ministry of Education), Hunan University, Changsha 410082, PR China
| | - Xuran Liu
- College of Environmental Science and Engineering and Key Laboratory of Environmental Biology and Pollution Control (Ministry of Education), Hunan University, Changsha 410082, PR China
| | - Qi Lu
- College of Environmental Science and Engineering and Key Laboratory of Environmental Biology and Pollution Control (Ministry of Education), Hunan University, Changsha 410082, PR China
| | - Dongbo Wang
- College of Environmental Science and Engineering and Key Laboratory of Environmental Biology and Pollution Control (Ministry of Education), Hunan University, Changsha 410082, PR China.
| |
Collapse
|
5
|
Lin Q, Dong X, Xi S, Cheng B, Zan F, Ma J, Liu X, Hao T, Guo G. Optimizing waste activated sludge disintegration by investigating multiple electrochemical pretreatment conditions: Performance, mechanism and modeling. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 870:162025. [PMID: 36739035 DOI: 10.1016/j.scitotenv.2023.162025] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/21/2022] [Revised: 01/14/2023] [Accepted: 01/31/2023] [Indexed: 06/18/2023]
Abstract
The complex and rigid floc structure often limits the reutilization of waste activated sludge (WAS). Electrochemical pretreatment (EPT) is one of the most effective technologies that can enhance WAS disintegration. But a comprehensive investigation into how multiple EPT conditions work was rarely reported. The study evaluated the effects of multiple EPT conditions, i.e., different electrolytes (NaCl, Na2SO4, and CaCl2), electrolytes dosage (0 g/L, 0.5 g/L, 1.0 g/L, and 3.0 g/L), EPT current (0 A, 0.5 A, 1.0 A, and 3.0 A) and EPT time (0 min, 30 min, 60 min, and 90 min) on WAS disintegration. The results showed that NaCl was outstanding from other electrolytes in promoting more WAS disintegration. Besides, a relatively higher NaCl dosage, a higher EPT current, and a longer EPT time promoted more reactive chlorine species (RCS), thus enhancing WAS disintegration in terms of extracellular polymeric substances (EPS) structure destruction and biodegradable organic matter release. After EPT for 60 min at NaCl dosage of 1.0 g/L and current of 1.0 A, the EPS multilayer structure destruction, biodegradable organic matters release, and soluble chemical oxygen demand (SCOD) increase in the supernatant were enhanced by 17.2 %, 130.5 %, and 238.7 %, respectively. Then a predictive quadratic model was established and the impact significance of the above EPT factors for enhancing WAS disintegration followed dosage of NaCl > current > EPT time. Furthermore, response surface methodology (RSM) suggested NaCl dosage of 2.75 g/L, current of 2.0 A, and EPT time of 30 min were the optimal EPT conditions, bringing a 42.0 % increase in the net economic benefit of WAS treatment compared to without EPT.
Collapse
Affiliation(s)
- Qingshan Lin
- School of Environmental Science and Engineering, Huazhong University of Science and Technology (HUST), Key Laboratory of Water and Wastewater Treatment (HUST), MOHURD, Wuhan 430074, China
| | - Xinlei Dong
- School of Environmental Science and Engineering, Huazhong University of Science and Technology (HUST), Key Laboratory of Water and Wastewater Treatment (HUST), MOHURD, Wuhan 430074, China
| | - Shihao Xi
- School of Environmental Science and Engineering, Huazhong University of Science and Technology (HUST), Key Laboratory of Water and Wastewater Treatment (HUST), MOHURD, Wuhan 430074, China
| | - Boyi Cheng
- School of Environmental Science and Engineering, Huazhong University of Science and Technology (HUST), Key Laboratory of Water and Wastewater Treatment (HUST), MOHURD, Wuhan 430074, China
| | - Feixiang Zan
- School of Environmental Science and Engineering, Huazhong University of Science and Technology (HUST), Key Laboratory of Water and Wastewater Treatment (HUST), MOHURD, Wuhan 430074, China
| | - Jie Ma
- Faculty of Resources and Environmental Science, Hubei University, Wuhan 430062, China
| | - Xiaoming Liu
- Department of Civil and Environmental Engineering, The Hong Kong University of Science and Technology, Hong Kong, China
| | - Tianwei Hao
- Department of Civil and Environmental Engineering, University of Macau, Macau
| | - Gang Guo
- School of Environmental Science and Engineering, Huazhong University of Science and Technology (HUST), Key Laboratory of Water and Wastewater Treatment (HUST), MOHURD, Wuhan 430074, China.
| |
Collapse
|
6
|
H2S Emission and Microbial Community of Chicken Manure and Vegetable Waste in Anaerobic Digestion: A Comparative Study. FERMENTATION-BASEL 2023. [DOI: 10.3390/fermentation9020169] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/16/2023]
Abstract
In order to solve the problem of H2S corrosion in biogas utilization, it is necessary to understand the characteristics and mechanisms of H2S production in chicken manure anaerobic digestion (CMAD) and vegetable waste anaerobic digestion (VWAD). In this study, lab-scale batch tests of CMAD and VWAD were conducted for 67 days at 35 °C. The results showed that sulfide was found to be the major form of sulfur in CMAD (accounting for 90%) and VWAD (70%). The average concentration of H2S was 198 ± 79 ppm in CMAD and 738 ± 210 ppm in VWAD. Moreover, 81% of total H2S was produced at 20 days of methane production in CMAD, but 80% of total H2S was produced in the first day in VWAD because of the rapid production of biogas and fermentation acidification. The sulfide ion equilibrium model could universally and feasibly predict the H2S production in CMAD and VWAD. The abundance of Firmicutes, Bacteroidetes, Proteobacteria and Euryarchaeota accounted for about 95% of the total microbes in both CMAD and VWAD; the influence of the fermentation stage on the microbial community was greater than that of the difference between CM and VW; the abundance of SRB was 0.01~0.07%, while that concerning organosulfur compounds fermentation was 22.8~30.5%. This study indicated that the H2S concentration of CMAD biogas was more than five times that of VWAD because CM is alkalescent but VW is acidic.
Collapse
|
7
|
Fu Q, Liu X, He D, Li X, Li C, Du M, Wang Y, Long S, Wang D. Rhamnolipid increases H 2S generation from waste activated sludge anaerobic fermentation: An overlooked concern. WATER RESEARCH 2022; 221:118742. [PMID: 35752095 DOI: 10.1016/j.watres.2022.118742] [Citation(s) in RCA: 20] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/22/2022] [Revised: 04/25/2022] [Accepted: 06/11/2022] [Indexed: 06/15/2023]
Abstract
Rhamnolipid (RL), one representative biosurfactant, is widely regarded as an economically feasible and environmentally beneficial additive to improve fermentation efficiency and resource recovery from waste activated sludge (WAS). However, its potentially detrimental impact on WAS fermentation such as H2S generation was overlooked previously. This study therefore aims to fill the gap through exploring whether and how the presence of RL affects H2S generation from WAS anaerobic fermentation. Experimental results showed that when RL increased from 0 to 40 mg/g total suspended solids (TSS), the cumulative H2S yield enhanced from 323.6 × 10-4 to 620.3 × 10-4 mg/g volatile suspended solids (VSS). Mechanism analysis showed that RL reduced WAS surface tension, which benefited transformations of organic sulfurs (e.g., aliphatic-S and sulfoxide) and inorganic sulfate from solid to liquid phase. The presence of RL not only reduced the ratio of α-helix/(β-sheet + random coil) and damaged the hydrogen bonding networks of organic sulfurs but also promoted substrate surface charges and cell membrane permeability. These facilitated the contact between hydrolase and organic sulfurs, thereby increasing sulfide production from organic sulfurs hydrolysis. Further investigations showed that RL promoted the expression of key genes (e.g., aprA/B and dsrA/B) involved in the dissimilatory sulfate reduction, which accelerated the reaction of adenosine 5'-phosphosulfate (APS)→ sulfite→ sulfide. Meanwhile, RL inhibited the corresponding key genes such as CysH, and Sir, responsible for assimilatory sulfate reduction (APS→3'-phosphoadenosine-5'phosphosulfate→organosulfur), which reduced substrate competition in favor of H2S production from dissimilatory sulfate reduction. Besides, RL decreased the fermentation pH, which benefited the transformation of HS- to H2S.
Collapse
Affiliation(s)
- Qizi Fu
- 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
| | - Xuran Liu
- 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
| | - Dandan He
- 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
| | - Xuemei 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
| | - Chenxi 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
| | - Mingting Du
- 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
| | - Yan 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
| | - Sha Long
- 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.
| |
Collapse
|
8
|
Das J, Ravishankar H, Lens PNL. Biological biogas purification: Recent developments, challenges and future prospects. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2022; 304:114198. [PMID: 34864410 DOI: 10.1016/j.jenvman.2021.114198] [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: 09/23/2021] [Revised: 11/11/2021] [Accepted: 11/26/2021] [Indexed: 06/13/2023]
Abstract
Raw biogas generated in the anaerobic digestion (AD) process contains several undesired constituents such as H2S, CO2, NH3, siloxanes and VOCs. These gases affect the direct application of biogas, and are a prime concern in biogas utilization processes. Conventional physico-chemical biogas purification methods are energy-intensive and expensive. To promote sustainable development and environmental friendly technologies, biological biogas purification technologies can be applied. This review describes biological technologies for both upstream and downstream processing in terms of pollutant removal mechanisms and efficiency, bioreactor configurations and different operating conditions. Limitations of the biological approaches and their future scope are also highlighted. A conceptual framework Driver-Pressure-Stress-Impact-Response (DPSIR) and Strengths-Weaknesses-Opportunities-Threats (SWOT) analysis have been applied to analyse the present situation and future scope of biological biogas clean-up technologies.
Collapse
Affiliation(s)
- Jewel Das
- National University of Ireland Galway, University Road, H91 TK33, Galway, Ireland; Bangladesh Council of Scientific and Industrial Research (BCSIR), BCSIR Laboratories Chattogram, Chattogram, 4220, Bangladesh.
| | - Harish Ravishankar
- National University of Ireland Galway, University Road, H91 TK33, Galway, Ireland
| | - Piet N L Lens
- National University of Ireland Galway, University Road, H91 TK33, Galway, Ireland
| |
Collapse
|
9
|
Zeng Q, Huang H, Tan Y, Chen G, Hao T. Emerging electrochemistry-based process for sludge treatment and resources recovery: A review. WATER RESEARCH 2022; 209:117939. [PMID: 34929476 DOI: 10.1016/j.watres.2021.117939] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/13/2021] [Revised: 11/17/2021] [Accepted: 12/04/2021] [Indexed: 06/14/2023]
Abstract
The electrochemical process is gaining widespread interest as an emerging alternative for sludge treatment. Its potentials for sludge stabilization and resources recovery have been well proven to date. Despite the high effectiveness of the electrochemical process having been highlighted in several studies, concerns about the electrochemical sludge treatment, including energy consumption, scale-up feasibility, and electrode stability, have not yet been addressed. The present paper critically reviews the versatile uses of the electrochemical processes for sludge treatment and resource recovery, from the fundamentals to the practical applications. Particularly considered are the enhancement of the digestion of the anaerobic sludge and dewaterability, removal of pathogens and heavy metals, and control of sludge malodor. In addition, the opportunities and challenges of the sludge-based resource recovery (i.e., nitrogen, phosphorus, and volatile fatty acids) are discussed. Insights into the working mechanisms (e.g., electroporation, electrokinetics and electrooxidation) of electrochemical processes are reviewed, and perspectives and future research directions are proposed. This work is expected to provide an in-depth understanding and broaden the potential applications of electrochemical processes for sludge treatment and resource recovery.
Collapse
Affiliation(s)
- Qian Zeng
- Department of Civil and Environmental Engineering, Chinese National Engineering Research Center for Control & Treatment of Heavy Metals Pollution (Hong Kong Branch) and Water Technology Center, The Hong Kong University of Science and Technology, Hong Kong, China
| | - Hao Huang
- Department of Civil and Environmental Engineering, Chinese National Engineering Research Center for Control & Treatment of Heavy Metals Pollution (Hong Kong Branch) and Water Technology Center, The Hong Kong University of Science and Technology, Hong Kong, China
| | - Yunkai Tan
- Department of Civil and Environmental Engineering, Faculty of Science and Technology, University of Macau, Macau, China
| | - Guanghao Chen
- Department of Civil and Environmental Engineering, Chinese National Engineering Research Center for Control & Treatment of Heavy Metals Pollution (Hong Kong Branch) and Water Technology Center, The Hong Kong University of Science and Technology, Hong Kong, China
| | - Tianwei Hao
- Department of Civil and Environmental Engineering, Faculty of Science and Technology, University of Macau, Macau, China
| |
Collapse
|
10
|
Yin R, Peng J, Sun J, Li C, Xia D, Shang C. Simultaneous removal of hydrogen sulfide, phosphate and emerging organic contaminants, and improvement of sludge dewaterability by oxidant dosing in sulfide-iron-laden sludge. WATER RESEARCH 2021; 203:117557. [PMID: 34418644 DOI: 10.1016/j.watres.2021.117557] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/26/2021] [Revised: 08/08/2021] [Accepted: 08/09/2021] [Indexed: 06/13/2023]
Abstract
Liquid sludge often contains odorous and toxic hydrogen sulfide and high levels of FeII compounds (e.g., iron sulfides), due to the extensive use of iron salts for hydrogen sulfide control in sewers and for enhanced primary treatment and phosphate removal in wastewater treatment plants. We proposed and verified that dosing appropriate chemical oxidants in the sulfide-iron-laden sludge can be a simple and cost-effective strategy to remove hydrogen sulfide, phosphate, and emerging organic contaminants, and to improve sludge dewaterability simultaneously. Among the seven oxidants investigated, H2O2, ClO2 and NaClO2 were the more cost-effective oxidants than others to control hydrogen sulfide release from the liquid sludge. Dosing these three oxidants also improved sludge dewaterability and removed dissolved phosphate from the liquid sludge, with H2O2 performing the best. Hydrogen sulfide was removed via both direct oxidation by the dosed oxidants and indirect oxidation by the FeIII that was in-situ formed from oxidation of the FeII compounds in the sludge. The in-situ formed FeIII also precipitated/adsorbed the soluble phosphate into the solid form (FePO4). Fenton-like reactions occurred between H2O2 and the FeII compounds in the sludge, and hydroxyl radicals (HO•) were generated. HO• oxidized hydrogen sulfide, destructed refractory organic emerging contaminants and sludge extracellular polymeric compounds (EPSs), and improved the sludge dewaterability. The formation of HO• can be enhanced by hydrogen sulfide and the sludge EPSs present in the sludge through providing more available FeII for the Fenton-like reactions. This study demonstrates the importance of selecting and dosing suitable oxidants to the sulfide-iron-laden sludge with due consideration for the multiple benefits in engineering practices. The same principles may be also used in formulating a dual oxidant-iron strategy to treat sulfide-iron-laden sewage, sludge, and sediments for simultaneous abatement of various pollutants.
Collapse
Affiliation(s)
- Ran Yin
- Department of Civil and Environmental Engineering, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong SAR, China
| | - Jiadong Peng
- Department of Civil and Environmental Engineering, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong SAR, China
| | - Jianliang Sun
- Guangdong Provincial Key Laboratory of Chemical Pollution and Environmental Safety & MOE Key Laboratory of Theoretical Chemistry of Environment, School of Environment, South China Normal University, Guangzhou 510006, China.
| | - Chenchen Li
- Department of Civil and Environmental Engineering, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong SAR, China
| | - Dehua Xia
- School of Environmental Science & Engineering, Sun Yat-sen University, Guangzhou, China
| | - Chii Shang
- Department of Civil and Environmental Engineering, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong SAR, China; Hong Kong Branch of Chinese National Engineering Research Center for Control & Treatment of Heavy Metal Pollution, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong SAR, China.
| |
Collapse
|
11
|
Zeng Q, Hao T, Yuan Z, Chen G. Dewaterability enhancement and sulfide mitigation of CEPT sludge by electrochemical pretreatment. WATER RESEARCH 2020; 176:115727. [PMID: 32259684 DOI: 10.1016/j.watres.2020.115727] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/11/2019] [Revised: 03/02/2020] [Accepted: 03/15/2020] [Indexed: 06/11/2023]
Abstract
Dewatering and sulfide control are the key challenges in treating chemically enhanced primary treatment (CEPT) sludge. In this study, an electrochemical pretreatment (EPT) approach with the input of 10 V/800 mA was explored for simultaneously improving the dewaterability of CEPT sludge and eliminating its sulfide production. The effects of different electrode materials (carbon and titanium) and EPT durations (from 5 to 15 min) were documented to reveal the underlying EPT mechanism. EPT with titanium electrodes (titanium-EPT) led to limited improvement in dewaterability and sulfide control. EPT with carbon electrodes (carbon-EPT) for 15 min, however, led to decreases in capillary suction time and specific resistance in filtration of over 80% and the suppression of about 99% of hydrogen sulfide (H2S(g)) production over 5 days of anaerobic storage. Analysis of the characteristics of treated CEPT sludge revealed that carbon-EPT disintegrated sludge flocs with ∼70% reduction in sludge particle sizes and release of aromatic and tyrosine protein-like substances, thus enhancing sludge dewaterability. The sulfur balance in the liquid and gaseous phases showed that most of the sulfur-containing compounds remained in the solid phase as aliphatic sulfur and sulfonic acid after carbon-EPT, thereby mitigating sulfide emission. While the pattern of sulfur distribution in sludge with titanium-EPT was dominated by sulfide, it was similar to the control sample. Reduction in bacteria associated with sulfide production (i.e., Lachnospiraceae) in CEPT sludge after carbon-EPT also contributed to sulfide elimination. This study demonstrates that EPT can be a superior option for simultaneously enhancing the dewaterability of CEPT sludge and mitigating its sulfide production.
Collapse
Affiliation(s)
- Qian Zeng
- Department of Civil and Environmental Engineering, The Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong, China
| | - Tianwei Hao
- Department of Civil and Environmental Engineering, Faculty of Science and Technology, University of Macau, Macau; Department of Civil and Environmental Engineering, The Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong, China.
| | - Zhiguo Yuan
- Advanced Water Management Centre, The University of Queensland, St. Lucia, Brisbane, QLD, 4072, Australia
| | - Guanghao Chen
- Department of Civil and Environmental Engineering, The Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong, China; Chinese National Engineering Research Center for Control & Treatment of Heavy Metal Pollution (Hong Kong Branch) and Water Technology Center, The Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong, China; Wastewater Treatment Laboratory, FYT Graduate School, The Hong Kong University of Science and Technology, Guangzhou, China
| |
Collapse
|