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Bhatia SK, Gurav R, Yang YH. A review on waste activated sludge pretreatment for improved volatile fatty acids production and their upcycling into polyhydroxyalkanoates. Int J Biol Macromol 2025; 308:142562. [PMID: 40154714 DOI: 10.1016/j.ijbiomac.2025.142562] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2024] [Revised: 03/21/2025] [Accepted: 03/25/2025] [Indexed: 04/01/2025]
Abstract
Waste activated sludge (WAS), a byproduct of wastewater treatment (WWTPs) facilities is challenging to manage because of its high organic content. Most of WAS is managed via anaerobic digestion (AD) to produce biogas, which is not deemed economically viable. The AD of WAS into volatile fatty acids (VFA) and their subsequent upcycling into polyhydroxyalkanoates (PHA) is gaining popularity due to their high value and uses. However, the fundamental issue with WAS is its low solubility, and pretreatment is required to increase it. Pretreatment disintegrates sludge floc and enhances its solubility, supports acetogens, and inhibits methanogens, leading to increased VFA synthesis in the AD process. The key factors influencing VFA yield include the size of the sludge granules, the mixing rate, and the presence of resistant organic components. Fermented broth containing VFA from AD can be utilized directly as a feedstock for microbial fermentation to produce PHA using both pure as well as mixed cultures. Utilisation of mixed cultures is useful since they are robust, able to consume a wide range of substrates, and do not require sterility. In addition, the VFA, which is made up of various organic acids, impacts the structure, productivity, characteristics, and type of PHA produced by microbial communities. Considering the importance of WAS management through VFA production and its integration with PHA production process this review article discusses the WAS pretreatment strategies, various factors that influence the AD process, trends in VFA to PHA production technologies with challenges, and possible solutions for integrated process development.
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Affiliation(s)
- Shashi Kant Bhatia
- Advanced Materials Program, Department of Biological Engineering, College of Engineering, Konkuk University, Seoul 05029, Republic of Korea; Institute for Ubiquitous Information Technology and Applications, Seoul 05029, Republic of Korea
| | - Ranjit Gurav
- Sustainability Cluster, School of Advanced Engineering, UPES, Dehradun 248007, Uttarakhand, India
| | - Yung-Hun Yang
- Advanced Materials Program, Department of Biological Engineering, College of Engineering, Konkuk University, Seoul 05029, Republic of Korea; Institute for Ubiquitous Information Technology and Applications, Seoul 05029, Republic of Korea.
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Wang X, Huang M, Chen S, Bi X, Wang L, Tang M, Liu Z, Huang Q, Gao S, Maletskyi Z. Alkalinity enhanced hydrolysis of primary sludge for carbon source recovery and its impact on denitrification in wastewater treatment. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2025; 373:123903. [PMID: 39733673 DOI: 10.1016/j.jenvman.2024.123903] [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: 08/24/2024] [Revised: 12/09/2024] [Accepted: 12/24/2024] [Indexed: 12/31/2024]
Abstract
Primary sludge can serve as an internal carbon source for denitrification in wastewater treatment plants (WWTPs). This study explores the use of alkaline treatment to produce a fermentation broth from primary sludge, which predominantly contains short-chain volatile fatty acids (VFAs), with acetic acid and propionic acid making up over 65% of the total VFAs. The performance of this fermentation broth as a sole carbon source for denitrification was compared with that of sodium acetate, acetic acid, methanol, and ethanol in both biofilm and activated sludge systems. The results revealed that the denitrification rate achieved using the fermentation broth was as high as 2.1661 mg NO3--N/(g MLSS·h), which was slightly lower than that of sodium acetate and acetic acid but higher than that of methanol and ethanol. The fermentation broth demonstrated a high heterotrophic yield (0.7183), an equivalent specific carbon requirement for denitrification as acetic acid and sodium acetate, and a rapid denitrification start-up. Moreover, variations in the VFAs/SCOD ratios in the fermentation broth did not significantly impact the denitrification rate or substrate biodegradation rate. However, the yield coefficient and specific carbon requirement for denitrification were found to vary significantly depending on the carbon source used. This study concludes that with appropriate treatment, fermented broth from primary sludge can be an effective carbon source comparable to commercial external carbon sources, significantly reducing carbon emissions.
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Affiliation(s)
- Xiaodong Wang
- School of Environmental and Municipal Engineering, Qingdao University of Technology, Jialingjiang Dong 777, Qingdao, 266520, China.
| | - Mei Huang
- School of Environmental and Municipal Engineering, Qingdao University of Technology, Jialingjiang Dong 777, Qingdao, 266520, China
| | - Shanshan Chen
- School of Environmental and Municipal Engineering, Qingdao University of Technology, Jialingjiang Dong 777, Qingdao, 266520, China
| | - Xuejun Bi
- School of Environmental and Municipal Engineering, Qingdao University of Technology, Jialingjiang Dong 777, Qingdao, 266520, China
| | - Ling Wang
- School of Environmental and Municipal Engineering, Qingdao University of Technology, Jialingjiang Dong 777, Qingdao, 266520, China
| | - Mingyue Tang
- Qingdao Capital Ruihai Water Co. Ltd, Ruihai Bei 2, Qingdao, 266042, China
| | - Zhen Liu
- Qingdao Capital Ruihai Water Co. Ltd, Ruihai Bei 2, Qingdao, 266042, China
| | - Qing Huang
- Qingdao Water Environmental Co. Ltd, Tuandao 3, Qingdao, 266001, China
| | - Shuai Gao
- Qingdao Water Environmental Co. Ltd, Tuandao 3, Qingdao, 266001, China
| | - Zakhar Maletskyi
- Faculty of Science and Technology, Norwegian University of Life Sciences, P.O. Box 5003, Aas, 1430, Norway
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3
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Qin W, Yang G, Chen K, Gao Y, Li J, Lin L, Hu E, Jiang J. Enhancing volatile fatty acid production through thermal hydrolysis of food waste with surfactant additives in anaerobic digestion. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2025; 373:123576. [PMID: 39642841 DOI: 10.1016/j.jenvman.2024.123576] [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: 08/11/2024] [Revised: 11/02/2024] [Accepted: 12/01/2024] [Indexed: 12/09/2024]
Abstract
The hydrolysis phase is recognized as the bottleneck in the anaerobic conversion of food waste. This study firstly investigates an innovative surfactant-enhanced thermal hydrolysis (STH) process, using alkyl polyglucoside (APG), a bio-based surfactant, in combination with improved response surface methodology (RSM) to optimize pretreatment conditions for volatile fatty acids (VFAs) production in anaerobic digestion (AD) of food waste. The synergistic effects of the coupled technology and its impact on acid production were explored, and the contributions of the pretreatment techniques were quantified. Results show that STH significantly enhances the solubilization of organic matter and VFAs yield. Under optimal conditions (110 °C, 0.005 g APG/g TSS), fermentation time is reduced in half, and VFAs production increases to 33.72 g COD/L. Overall, this research solidifies the substantial potential of STH in improving the solubilization, hydrolysis, and VFAs production efficiency from food waste and sets the stage for its industrial-scale application in VFA production, offering valuable insights into optimizing food waste resource utilization.
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Affiliation(s)
- Weikai Qin
- School of Environment, Tsinghua University, Beijing, 100084, China
| | - Guodong Yang
- School of Environment, Harbin Institute of Technology, Heilongjiang Province, Harbin, 150001, China; School of Environmental Science and Engineering, South University of Science and Technology, Guangdong Province, Shenzhen, 518055, China; City Appearance and Environment Management & Service Center of Shenzhen Bao'an District, Guangdong Province, Shenzhen, 518101, China
| | - Kailun Chen
- School of Environment, Tsinghua University, Beijing, 100084, China
| | - Yuchen Gao
- School of Environment, Tsinghua University, Beijing, 100084, China
| | - Jinglin Li
- School of Environment, Tsinghua University, Beijing, 100084, China
| | - Li Lin
- School of Environment, Tsinghua University, Beijing, 100084, China
| | - Endian Hu
- School of Environment, Tsinghua University, Beijing, 100084, China
| | - Jianguo Jiang
- School of Environment, Tsinghua University, Beijing, 100084, China.
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Li XQ, Yu Z, Lin Z, Fang YK, Sun Q, Chen K, Wang AJ, Liu WZ. Unveiling the common laws of extracellular polymeric substances (EPS) properties on short-chain fatty acids production from sludge by EPS disintegration pretreatment. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 950:175286. [PMID: 39111431 DOI: 10.1016/j.scitotenv.2024.175286] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/28/2024] [Revised: 07/30/2024] [Accepted: 08/02/2024] [Indexed: 08/10/2024]
Abstract
The production of short-chain fatty acids (SCFAs) from sludge is promising, but the efficiency and product quality often vary because of extracellular polymeric substances (EPS) characteristics and pretreatment principles. This study adopted specific EPS disintegration pretreatment to treat different types of sludge. By correlation coefficient matrix analysis and correlation dynamics change resolution, the intrinsic relationships between the nature of EPS and the production of SCFAs from sludge was unveiled. We demonstrate that tight-bound EPS (TB-EPS) is a principal carbon reservoir, positively impacting SCFAs yields, in the fermentation system with EPS as the main fermentation substrate, it can contribute about 29.2 % for SCFAs growth during fermentation. Conversely, TB-EPS exhibits a negative correlation during fermentation due to EPS-SCFAs interconversion, while loosely bound EPS (LB-EPS) correlates positively. Proteins and polysaccharides in TB-EPS, especially proteins, significantly enhance individual SCFAs yields, predominantly acetic, propionic, and isovaleric acids. The findings would provide a theoretical basis for developing pretreatments and process-control technologies aimed at improving SCFAs production efficiency and quality.
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Affiliation(s)
- Xi-Qi Li
- State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, Harbin 150090, China; State Key Laboratory of Urban Water Resource and Environment, School of Civil and Environmental Engineering, Harbin Institute of Technology Shenzhen, Shenzhen 518055, China; CAS Key Laboratory of Environmental Biotechnology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
| | - Zhe Yu
- State Key Laboratory of Urban Water Resource and Environment, School of Civil and Environmental Engineering, Harbin Institute of Technology Shenzhen, Shenzhen 518055, China
| | - Zhen Lin
- Shanghai Municipal Engineering Design & Research Institute (Group) Co. Ltd, Shanghai 200092, China
| | - Ying-Ke Fang
- School of Ecology and Environment, Zhengzhou University, Zhengzhou 450002, China
| | - Qi Sun
- CAS Key Laboratory of Environmental Biotechnology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
| | - Kan Chen
- State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, Harbin 150090, China
| | - Ai-Jie Wang
- State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, Harbin 150090, China; State Key Laboratory of Urban Water Resource and Environment, School of Civil and Environmental Engineering, Harbin Institute of Technology Shenzhen, Shenzhen 518055, China; CAS Key Laboratory of Environmental Biotechnology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
| | - Wen-Zong Liu
- State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, Harbin 150090, China; State Key Laboratory of Urban Water Resource and Environment, School of Civil and Environmental Engineering, Harbin Institute of Technology Shenzhen, Shenzhen 518055, China.
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Zhao Z, Zheng X, Yang S, He H, Han Z, Li W, Lin T, Xu H. Influence of perfluorooctanoic acid on alkaline anaerobic fermentation of waste activated sludge: Perspective from volatile fatty acids production and sludge reduction. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2024; 370:122581. [PMID: 39303591 DOI: 10.1016/j.jenvman.2024.122581] [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: 06/19/2024] [Revised: 08/27/2024] [Accepted: 09/16/2024] [Indexed: 09/22/2024]
Abstract
Alkaline anaerobic fermentation is an effective approach for resource utilization and reduction of waste activated sludge (WAS). Perfluorooctanoic acid (PFOA) is widespread in WAS, however, its potential impact on alkaline anaerobic fermentation of WAS remains largely unknown. Hence, this study focused on investigating the influence of PFOA on volatile fatty acids (VFAs) production and sludge reduction during alkaline anaerobic fermentation (pH = 10 ± 0.1), as well as the critical mechanisms. Results demonstrated that low PFOA concentration (5 mg/kg-TS) raised VFAs yield to 109.37%, while high levels of PFOA (25 and 50 mg/kg-TS) remarkably decreased VFAs production to 89.55% and 80.44% of the control. Mechanism exploration revealed that PFOA facilitated the solubilization process, and low PFOA level enhanced the accumulation of VFAs via increased bioavailable substrates and the activities of enzymes and microorganisms. On the contrary, high levels of PFOA were substantial biotoxicity, inducing excessive ROS production, causing oxidative damage, and reducing enzyme activity and functional microbial abundance, thereby decreasing VFAs production. Additionally, further analysis of sludge physicochemical properties confirmed that the effect of PFOA on WAS reduction exhibited the same trend as VFAs production. This work provides a basis for PFOA environmental risk assessment and WAS resource utilization.
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Affiliation(s)
- Zhilin Zhao
- Ministry of Education Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Hohai University, Nanjing 210098, PR China; College of Environment, Hohai University, Nanjing 210098, PR China
| | - Xiaoying Zheng
- Ministry of Education Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Hohai University, Nanjing 210098, PR China; College of Environment, Hohai University, Nanjing 210098, PR China.
| | | | - Haidong He
- Ministry of Education Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Hohai University, Nanjing 210098, PR China; College of Environment, Hohai University, Nanjing 210098, PR China
| | - Zongshuo Han
- Ministry of Education Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Hohai University, Nanjing 210098, PR China; College of Environment, Hohai University, Nanjing 210098, PR China
| | - Wenfei Li
- Ministry of Education Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Hohai University, Nanjing 210098, PR China; College of Environment, Hohai University, Nanjing 210098, PR China
| | - Tao Lin
- Ministry of Education Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Hohai University, Nanjing 210098, PR China; College of Environment, Hohai University, Nanjing 210098, PR China
| | - Hang Xu
- Ministry of Education Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Hohai University, Nanjing 210098, PR China; College of Environment, Hohai University, Nanjing 210098, PR China
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Ma M, Duan W, Huang X, Zeng D, Hu L, Gui W, Zhu G, Jiang J. Application of calcium peroxide in promoting resource recovery from municipal sludge: A review. CHEMOSPHERE 2024; 354:141704. [PMID: 38490612 DOI: 10.1016/j.chemosphere.2024.141704] [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: 12/07/2023] [Revised: 02/26/2024] [Accepted: 03/11/2024] [Indexed: 03/17/2024]
Abstract
The harmless disposal, resource recovery, and synergistic efficiency reduction of municipal sludge have been the research focuses for the last few years. Calcium peroxide (CaO2) is a multifunctional and safe peroxide that produces an alkaline oxidation environment to promote the fermentation of municipal sludge to produce hydrogen (H2) and volatile fatty acids (VFAs), thus realizing sludge resource recovery. This review outlines the research achievements of CaO2 in sludge resource recovery, improvement of sludge dewaterability, and removal of pollutants from sludge in recent years. Meanwhile, the mechanism of CaO2 and its influencing factors have also been comprehensively summarized. Finally, the future development direction of the application of CaO2 in municipal sludge is prospected. This review would provide theoretical reference for the potential engineering applications of CaO2 in improving sludge treatment in the future.
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Affiliation(s)
- Mengsha Ma
- Collaborative Innovation Center of Atmospheric Environment and Equipment Technology, Jiangsu Key Laboratory of Atmospheric Environment Monitoring and Pollution Control, School of Environmental Science and Engineering, Nanjing University of Information Science & Technology, Nanjing, 210044, China
| | - Weiyan Duan
- Ocean College of Hebei Agricultural University, Qinhuangdao, Hebei Province, China
| | - Xiao Huang
- Collaborative Innovation Center of Atmospheric Environment and Equipment Technology, Jiangsu Key Laboratory of Atmospheric Environment Monitoring and Pollution Control, School of Environmental Science and Engineering, Nanjing University of Information Science & Technology, Nanjing, 210044, China; Shenzhen Key Laboratory of Water Resources Utilization and Environmental Pollution Control, School of Civil and Environmental Engineering, Harbin Institute of Technology (Shenzhen), Shenzhen, 518055, China.
| | - Daojing Zeng
- Collaborative Innovation Center of Atmospheric Environment and Equipment Technology, Jiangsu Key Laboratory of Atmospheric Environment Monitoring and Pollution Control, School of Environmental Science and Engineering, Nanjing University of Information Science & Technology, Nanjing, 210044, China
| | - Liangshan Hu
- Collaborative Innovation Center of Atmospheric Environment and Equipment Technology, Jiangsu Key Laboratory of Atmospheric Environment Monitoring and Pollution Control, School of Environmental Science and Engineering, Nanjing University of Information Science & Technology, Nanjing, 210044, China
| | - Wenjing Gui
- Collaborative Innovation Center of Atmospheric Environment and Equipment Technology, Jiangsu Key Laboratory of Atmospheric Environment Monitoring and Pollution Control, School of Environmental Science and Engineering, Nanjing University of Information Science & Technology, Nanjing, 210044, China
| | - Gaoming Zhu
- Collaborative Innovation Center of Atmospheric Environment and Equipment Technology, Jiangsu Key Laboratory of Atmospheric Environment Monitoring and Pollution Control, School of Environmental Science and Engineering, Nanjing University of Information Science & Technology, Nanjing, 210044, China
| | - Jiahong Jiang
- New York University, New York, NY, 10012, United States
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Ding W, Fan X, Zhou X, Liu R, Chen C, Jin W, Sun J, Li X, Jiang G, Liu H. Performance and mechanisms of zero valent iron enhancing short-chain fatty acids production during thermophilic anaerobic fermentation of waste activated sludge. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 912:169025. [PMID: 38056647 DOI: 10.1016/j.scitotenv.2023.169025] [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: 09/28/2023] [Revised: 11/28/2023] [Accepted: 11/29/2023] [Indexed: 12/08/2023]
Abstract
This work first explored the feasibility and possible mechanisms of zero valent iron (ZVI) pretreatment on the generation of short-chain fatty acids (SCFAs) during thermophilic anaerobic fermentation of waste activated sludge (WAS). Results showed that ZVI enhanced the quantity of SCFAs. On Day 6, the SCFAs production reached 455.84 ± 47.88 mg COD/g VSS at 5 g/L of ZVI addition, which increased by 63.80 % relative to control. The presence of ZVI can effectively promote butyric-based fermentation. ZVI accelerated the destruction of extracellular polymeric substances (EPS) and interior sludge cells, as well as improved biodegradation of soluble organics. Also, ZVI enhanced key enzyme activities (i.e., BK and CoA-), thus promoting degradation rates of acidogenesis (6.30 ± 0.84 mg/(gVSS·h) in glucose) and acetogenesis (74.63 ± 0.29 mg/(gVSS·h) in butyrate). Compared to Fe(III), the contribution of Fe(II) was higher among the decomposition products of ZVI. Besides, ZVI favored Proteobacteria and Actinobacteria, which enhanced acetate formation and organic compounds disassimilation of the process, respectively. The abundance of Tepidiphilus, Thermobrachium and Tepidimicrobium was increased, indicating promoting the system stability of SCFAs production in thermophilic anaerobic fermentation.
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Affiliation(s)
- Wanqing Ding
- State Key Laboratory of Urban Water Resource and Environment, School of Civil and Environmental Engineering, Harbin Institute of Technology (Shenzhen), Shenzhen, Guangdong 518055, China
| | - Xiumin Fan
- Shenzhen Ecological and Environmental Intelligent Management and Control Center, Shenzhen 518034, China
| | - Xu Zhou
- State Key Laboratory of Urban Water Resource and Environment, School of Civil and Environmental Engineering, Harbin Institute of Technology (Shenzhen), Shenzhen, Guangdong 518055, China.
| | - Ruining Liu
- State Key Laboratory of Urban Water Resource and Environment, School of Civil and Environmental Engineering, Harbin Institute of Technology (Shenzhen), Shenzhen, Guangdong 518055, China
| | - Chuan Chen
- State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, Harbin, Heilongjiang Province 150090, China
| | - Wenbiao Jin
- State Key Laboratory of Urban Water Resource and Environment, School of Civil and Environmental Engineering, Harbin Institute of Technology (Shenzhen), Shenzhen, Guangdong 518055, China
| | - Jing Sun
- State Key Laboratory of Pollution Control and Resource Reuse, Key Laboratory of Yangtze River Water Environment, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, China
| | - Xuan Li
- Centre for Technology in Water and Wastewater, School of Civil and Environmental Engineering, University of Technology Sydney, Ultimo, NSW 2007, Australia
| | - Guangming Jiang
- School of Civil, Mining and Environmental Engineering, University of Wollongong, NSW 2522, Wollongong, Australia
| | - Huan Liu
- Centre for Technology in Water and Wastewater, School of Civil and Environmental Engineering, University of Technology Sydney, Ultimo, NSW 2007, Australia
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Ma K, Han X, Li Q, Kong Y, Liu Q, Yan X, Luo Y, Li X, Wen H, Cao Z. Improved anaerobic sludge fermentation mediated by a tryptophan-degrading consortium: Effectiveness assessment and mechanism deciphering. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2024; 350:119623. [PMID: 38029496 DOI: 10.1016/j.jenvman.2023.119623] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/15/2023] [Revised: 10/28/2023] [Accepted: 11/15/2023] [Indexed: 12/01/2023]
Abstract
The hydrolysis of extracellular polymeric substances (EPS) represents a critical bottleneck in the anaerobic fermentation of waste activated sludge (WAS), while tryptophan is identified as an underestimated constituent of EPS. Herein, we harnessed a tryptophan-degrading microbial consortium (TDC) to enhance the hydrolysis efficiency of WAS. At TDC dosages of 5%, 10%, and 20%, a notable increase in SCOD was observed by factors of 1.13, 1.39, and 1.88, respectively. The introduction of TDC improved both the yield and quality of short chain fatty acids (SCFAs), the maximum SCFA yield increased from 590.6 to 1820.2, 1957.9 and 2194.9 mg COD/L, whilst the acetate ratio within SCFAs was raised from 34.1% to 61.2-70.9%. Furthermore, as TDC dosage increased, the relative activity of protease exhibited significant increments, reaching 116.3%, 168.0%, and 266.1%, respectively. This enhancement facilitated WAS solubilization and the release of organic substances from bound EPS into soluble EPS. Microbial analysis identified Tetrasphaera and Soehngenia as key participants in WAS solubilization and the breakdown of protein fraction. Metabolic analysis revealed that TDC triggered the secretion of enzymes associated with amino acid metabolism and fatty acid biosynthesis, thereby fostering the decomposition of proteins and production of SCFAs.
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Affiliation(s)
- Kaili Ma
- School of Environment, Henan Normal University, Key Laboratory of Yellow River and Huai River Water Environment and Pollution Control, Ministry of Education, Xinxiang, 453000, China.
| | - Xinxin Han
- School of Environment, Henan Normal University, Key Laboratory of Yellow River and Huai River Water Environment and Pollution Control, Ministry of Education, Xinxiang, 453000, China
| | - Qiujuan Li
- School of Environment, Henan Normal University, Key Laboratory of Yellow River and Huai River Water Environment and Pollution Control, Ministry of Education, Xinxiang, 453000, China
| | - Yu Kong
- School of Environment, Henan Normal University, Key Laboratory of Yellow River and Huai River Water Environment and Pollution Control, Ministry of Education, Xinxiang, 453000, China
| | - Qiaoli Liu
- School of Environment, Henan Normal University, Key Laboratory of Yellow River and Huai River Water Environment and Pollution Control, Ministry of Education, Xinxiang, 453000, China
| | - Xu Yan
- School of Environment, Henan Normal University, Key Laboratory of Yellow River and Huai River Water Environment and Pollution Control, Ministry of Education, Xinxiang, 453000, China
| | - Yahong Luo
- School of Environment, Henan Normal University, Key Laboratory of Yellow River and Huai River Water Environment and Pollution Control, Ministry of Education, Xinxiang, 453000, China
| | - Xiaopin Li
- School of Environment, Henan Normal University, Key Laboratory of Yellow River and Huai River Water Environment and Pollution Control, Ministry of Education, Xinxiang, 453000, China
| | - Huiyang Wen
- School of Environment, Henan Normal University, Key Laboratory of Yellow River and Huai River Water Environment and Pollution Control, Ministry of Education, Xinxiang, 453000, China
| | - Zhiguo Cao
- School of Environment, Henan Normal University, Key Laboratory of Yellow River and Huai River Water Environment and Pollution Control, Ministry of Education, Xinxiang, 453000, China
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Gao J, Li L, Yuan S, Sun J, Chen S, Dong B. Reconceptualization of the mechanism of thermal hydrolysis pretreatment to enhance the anaerobic conversion of sludge organic nitrogen: Decisive role of organic nitrogen occurrence. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 899:165703. [PMID: 37487905 DOI: 10.1016/j.scitotenv.2023.165703] [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: 06/06/2023] [Revised: 07/18/2023] [Accepted: 07/19/2023] [Indexed: 07/26/2023]
Abstract
The occurrence state of organic nitrogen (ON) is the key to affect anaerobic biotransformation of sludge. ON in sludge was chemically classified as PA (easily accessible part), PB (moderately accessible) and PC (hardly accessible) according to the modified CNCPS method. The components of them were analyzed by PY-GCMS, and it was identified that PA was extracellular amino acids, peptides and proteins; PB was genetic material, cell wall peptidoglycans and intracellular proteins; PC was ON that cross-linked with complex macromolecules. The conversion characteristics of PA, PB and PC in sludge and their relationship with anaerobic digestion (AD) performance were investigated after thermal hydrolysis pretreatment (THP) at different temperatures (100-180 °C). With the increase of THP temperature, the hydrolysis of PA and the conversion of PB to PA were promoted. At 180-THP, part of PA was converted to PC due to thermochemical reactions. In the fast degradation stage of AD of ON (ON-fast), PA is the main component of degradation; while in the slow degradation stage (ON-slow), the degradation of ON is mainly dominated by PB. Therefore, THP can significantly increase the proportion of ON-fast and reduce the ON fraction in the digestate (ON-hard). Moreover, PA and PB, rather than PC, were identified as dominant in ON-hard with or without THP for the first time, overturning the traditional view (remaining ON after AD was that cross-linked with complex macromolecules). This is due to that PA and PB are the main ON that make up microbial cells. The findings upgraded our perspective on conversion of ON of sludge during AD and inspire the shifted focus from "degrading PC" to "PC accumulation" for later use, through targeted enhanced PA degradation.
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Affiliation(s)
- Jun Gao
- State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, China
| | - Lei Li
- State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, China
| | - Shijie Yuan
- State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, China
| | - Jing Sun
- State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, China
| | - Sisi Chen
- State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, China.
| | - Bin Dong
- State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, China; YANGTZE Eco-Environment Engineering Research Center, China Three Gorges Corporation, Beijing, China.
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10
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Jiang N, Zhang A, Miruka AC, Wang L, Li X, Xue G, Liu Y. Synergistic effects and mechanisms of plasma coupled with peracetic acid in enhancing short-chain fatty acid production from sludge: Motivation of reactive species and metabolic tuning of microbial communities. BIORESOURCE TECHNOLOGY 2023; 387:129618. [PMID: 37544535 DOI: 10.1016/j.biortech.2023.129618] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/04/2023] [Revised: 07/28/2023] [Accepted: 08/01/2023] [Indexed: 08/08/2023]
Abstract
Suitable waste activated sludge (WAS) pretreatments that boost short-chain fatty acid (SCFA) production from anaerobic fermentation are essential for carbon emission reduction and sludge resource utilization. This study established an efficient WAS pretreatment process combining atmospheric pressure plasma jet (APPJ) with peracetic acid (PAA). The maximum SCFA production (6.5-fold that of the control) largely increased under the optimal conditions (PAA dosage = 25 mg/g VSS (volatile suspended solids), energy consumption = 20.9 kWh/m3). APPJ/PAA pretreatment enhanced the production of multiple reactive species (including OH, CH3C(O)O, 1O2, ONOO-, O2-, and eaq-) and strengthened the effects of H2O2, heat, and light. This synergistically solubilized WAS and released organic substrates for SCFA-producing microbes. In addition, the enrichment of SCFA-producing bacteria and the decrease in SCFA-consuming bacteria favored SCFA accumulation. The key genes encoding for the main substrate metabolism and SCFA production in the metabolic pathway of fermentation were also enhanced.
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Affiliation(s)
- Nan Jiang
- College of Environmental Science and Engineering, Donghua University, 2999 North Renmin Road, Shanghai 201620, China
| | - Ai Zhang
- College of Environmental Science and Engineering, Donghua University, 2999 North Renmin Road, Shanghai 201620, China; Shanghai Institute of Pollution Control and Ecological Security, Shanghai 200092, China; National Circular Economy Engineering Laboratory, Shanghai 201620, China.
| | - Andere Clement Miruka
- College of Environmental Science and Engineering, Donghua University, 2999 North Renmin Road, Shanghai 201620, China; School of Chemistry and Material Science, Technical University of Kenya, Nairobi 52428-00200, Kenya
| | - Lin Wang
- Shanghai Institute of Pollution Control and Ecological Security, Shanghai 200092, China; State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, China
| | - Xiang Li
- College of Environmental Science and Engineering, Donghua University, 2999 North Renmin Road, Shanghai 201620, China
| | - Gang Xue
- College of Environmental Science and Engineering, Donghua University, 2999 North Renmin Road, Shanghai 201620, China
| | - Yanan Liu
- College of Environmental Science and Engineering, Donghua University, 2999 North Renmin Road, Shanghai 201620, China; Shanghai Institute of Pollution Control and Ecological Security, Shanghai 200092, China; National Circular Economy Engineering Laboratory, Shanghai 201620, China
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11
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Guan SW, Lin Q, Wu XD, Yu HB. Weighted gene coexpression network analysis and machine learning reveal oncogenome associated microbiome plays an important role in tumor immunity and prognosis in pan-cancer. J Transl Med 2023; 21:537. [PMID: 37573394 PMCID: PMC10422781 DOI: 10.1186/s12967-023-04411-0] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2023] [Accepted: 08/02/2023] [Indexed: 08/14/2023] Open
Abstract
BACKGROUND For many years, the role of the microbiome in tumor progression, particularly the tumor microbiome, was largely overlooked. The connection between the tumor microbiome and the tumor genome still requires further investigation. METHODS The TCGA microbiome and genome data were obtained from Haziza et al.'s article and UCSC Xena database, respectively. Separate WGCNA networks were constructed for the tumor microbiome and genomic data after filtering the datasets. Correlation analysis between the microbial and mRNA modules was conducted to identify oncogenome associated microbiome module (OAM) modules, with three microbial modules selected for each tumor type. Reactome analysis was used to enrich biological processes. Machine learning techniques were implemented to explore the tumor type-specific enrichment and prognostic value of OAM, as well as the ability of the tumor microbiome to differentiate TP53 mutations. RESULTS We constructed a total of 182 tumor microbiome and 570 mRNA WGCNA modules. Our results show that there is a correlation between tumor microbiome and tumor genome. Gene enrichment analysis results suggest that the genes in the mRNA module with the highest correlation with the tumor microbiome group are mainly enriched in infection, transcriptional regulation by TP53 and antigen presentation. The correlation analysis of OAM with CD8+ T cells or TAM1 cells suggests the existence of many microbiota that may be involved in tumor immune suppression or promotion, such as Williamsia in breast cancer, Biostraticola in stomach cancer, Megasphaera in cervical cancer and Lottiidibacillus in ovarian cancer. In addition, the results show that the microbiome-genome prognostic model has good predictive value for short-term prognosis. The analysis of tumor TP53 mutations shows that tumor microbiota has a certain ability to distinguish TP53 mutations, with an AUROC value of 0.755. The tumor microbiota with high importance scores are Corallococcus, Bacillus and Saezia. Finally, we identified a potential anti-cancer microbiota, Tissierella, which has been shown to be associated with improved prognosis in tumors including breast cancer, lung adenocarcinoma and gastric cancer. CONCLUSION There is an association between the tumor microbiome and the tumor genome, and the existence of this association is not accidental and could change the landscape of tumor research.
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Affiliation(s)
- Shi-Wei Guan
- Department of Hepatobiliary Surgery, Wenzhou Central Hospital, The Dingli Clinical Institute of Wenzhou Medical University, Wenzhou, 325000, Zhejiang, People's Republic of China
| | - Quan Lin
- Department of Hepatobiliary Surgery, Wenzhou Central Hospital, The Dingli Clinical Institute of Wenzhou Medical University, Wenzhou, 325000, Zhejiang, People's Republic of China
| | - Xi-Dong Wu
- Department of Neurosurgery Surgery, Wenzhou Central Hospital, The Dingli Clinical Institute of Wenzhou Medical University, Wenzhou, 325000, Zhejiang, People's Republic of China
| | - Hai-Bo Yu
- Department of Hepatobiliary Surgery, Wenzhou Central Hospital, The Dingli Clinical Institute of Wenzhou Medical University, Wenzhou, 325000, Zhejiang, People's Republic of China.
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12
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Xiang Z, Huang X, Chen H, Liu B, Liu Z, Dong W, Wang H. Insights into thermal hydrolysis pretreatment temperature for enhancing volatile fatty acids production from sludge fermentation: Performance and mechanism. BIORESOURCE TECHNOLOGY 2023; 379:129032. [PMID: 37031805 DOI: 10.1016/j.biortech.2023.129032] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/19/2023] [Revised: 04/04/2023] [Accepted: 04/06/2023] [Indexed: 05/03/2023]
Abstract
To reveal the impact of thermal hydrolysis pretreatment (THP) temperature on the unclear mechanisms of volatile fatty acids (VFAs) production, four groups were established with different temperatures (100, 120, 140 and 160 °C), and high throughput sequencing technology was utilized. The results indicated that the optimal VFAs production occurred at 140 °C. Moreover, as the THP temperature increased, the proportion of acetic acid also increased, accounting for 10.8% to 26.7% of the VFAs, compared to only 4.9% in the control group. Mechanism investigations revealed that THP facilitated the hydrolysis and release of biodegradable organic matter. Moreover, the abundance of VFAs production and hydrolytic microorganisms and related metabolic functional genes expression were evidently improved by THP. Overall, this study deepens the understanding of the mechanisms through which different THP temperatures stimulate the production of VFAs through acidogenic fermentation, providing technical support for future THP application in sludge treatment.
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Affiliation(s)
- Zhuangzhuang Xiang
- College of Environmental Science and Engineering, Ocean University of China, Qingdao 266100, China
| | - Xiao Huang
- Collaborative Innovation Center of Atmospheric Environment and Equipment Technology, Jiangsu Key Laboratory of Atmospheric Environment Monitoring and Pollution Control, School of Environmental Science and Engineering, Nanjing University of Information Science & Technology, Nanjing 210044, China; State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing 100084, China.
| | - Hanfeng Chen
- Collaborative Innovation Center of Atmospheric Environment and Equipment Technology, Jiangsu Key Laboratory of Atmospheric Environment Monitoring and Pollution Control, School of Environmental Science and Engineering, Nanjing University of Information Science & Technology, Nanjing 210044, China
| | - Biming Liu
- State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing 100084, China
| | - Ziming Liu
- Collaborative Innovation Center of Atmospheric Environment and Equipment Technology, Jiangsu Key Laboratory of Atmospheric Environment Monitoring and Pollution Control, School of Environmental Science and Engineering, Nanjing University of Information Science & Technology, Nanjing 210044, China
| | - Wenyi Dong
- School of Civil and Environmental Engineering, Harbin Institute of Technology Shenzhen, Shenzhen Key Laboratory of Water Resource Utilization and Environmental Pollution Control, Shenzhen 518055, China
| | - Hongjie Wang
- School of Civil and Environmental Engineering, Harbin Institute of Technology Shenzhen, Shenzhen Key Laboratory of Water Resource Utilization and Environmental Pollution Control, Shenzhen 518055, China
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13
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Wen L, Lin L, Fan YA, Luo Y, Ma SS, Zhou Y, Yang C, Shih K, Li XY. Valorization of thermally hydrolyzed sludge with clay for sintering of ceramic tiles. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 877:162871. [PMID: 36933740 DOI: 10.1016/j.scitotenv.2023.162871] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/07/2023] [Revised: 03/07/2023] [Accepted: 03/10/2023] [Indexed: 05/06/2023]
Abstract
The disposal of wastewater sludge is one of the most challenging environmental problems for large cities. Wastewater sludge may be utilized as a feasible substitute for clay to sinter ceramics, given their similar mineralogical composition. However, the organics in sludge will be wasted, while their release during sintering will leave cracks in the ceramic products. In this research, after the thermal treatment for effective organic recovery, the thermally hydrolyzed sludge (THS) is incorporated with clay for the sintering of construction ceramics. The experimental results showed that a THS dosing ratio up to 40 % can be achieved for mixing with montmorillonite clay to make ceramic tiles. The sintered tiles (THS-40) had an intact shape and structure, and the tile performance was close to that made from single montmorillonite (THS-0), with water absorption of 0.4 % vs. 0.2 %, compressive strength of 136.8 vs. 140.7 MPa, and undetected heavy metal leaching. Further addition of THS would lead to a considerable deterioration of the quality of the tiles to a compressive strength of as low as 5.0 MPa for the THS only product (THS-100). Comparing with the tiles incorporated with raw sludge (RS-40), the THS-40 tiles had a more intact and denser structure with a 10 % improved compressive strength. Cristobalite, aluminum phosphate, mullite, and hematite dominated in the THS-born ceramics, which are typical components of ceramics, and the amount of hematite increased with the THS dosing ratio. Sintering at a high temperature of 1200 °C enabled efficient phase transformation from quartz to cristobalite and from muscovite to mullite, which ensured the toughness and compactness of the THS-born ceramic tiles.
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Affiliation(s)
- Lei Wen
- Department of Civil Engineering, The University of Hong Kong, Pokfulam, Hong Kong
| | - Lin Lin
- Institute of Environment and Ecology, Tsinghua Shenzhen International Graduate School, Tsinghua University, Shenzhen 518055, China.
| | - Yi-Ang Fan
- Department of Civil Engineering, The University of Hong Kong, Pokfulam, Hong Kong
| | - Yang Luo
- Department of Materials, ETH Zürich, Vladimir-Prelog-Weg 5, Zurich 8093, Switzerland
| | - Sheng-Shou Ma
- Department of Civil Engineering, The University of Hong Kong, Pokfulam, Hong Kong
| | - Ying Zhou
- Department of Civil Engineering, The University of Hong Kong, Pokfulam, Hong Kong
| | - Chao Yang
- Department of Civil Engineering, The University of Hong Kong, Pokfulam, Hong Kong
| | - Kaimin Shih
- Department of Civil Engineering, The University of Hong Kong, Pokfulam, Hong Kong
| | - Xiao-Yan Li
- Department of Civil Engineering, The University of Hong Kong, Pokfulam, Hong Kong; Institute of Environment and Ecology, Tsinghua Shenzhen International Graduate School, Tsinghua University, Shenzhen 518055, China.
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14
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Liu L, Pan Y, Zhi X, Chen L, Zhu H. Bacterial antioxidant mechanism in calcium peroxide aided sludge anaerobic fermentation. BIORESOURCE TECHNOLOGY 2023; 384:129327. [PMID: 37328013 DOI: 10.1016/j.biortech.2023.129327] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/03/2023] [Revised: 05/13/2023] [Accepted: 06/11/2023] [Indexed: 06/18/2023]
Abstract
Although calcium peroxide (CaO2) can enhance the short-chain fatty acids (SCFAs) production in sludge anaerobic fermentation, the microbiological mechanisms underlying this process remain unclear. In this study, it is aimed to elucidate the bacterial protective mechanisms in response to the oxidative stress induced by CaO2. Results show that extracellular polymeric substance (EPS) and anti-oxidant enzymes play vital roles in protecting bacterial cells from CaO2. The addition of CaO2 resulted in increased relative abundances of genes exoP and SRP54, which are associated with EPS secretion and transportation. Superoxide dismutase (SOD) played a crucial in alleviating oxidative stress. The dosage of CaO2 significantly influences the succession of the bacterial community in the anaerobic fermentation system. With 0.3 g CaO2/g VSS, the net income was approximately 4 USD/ton of sludge treated. The CaO2-assisted anaerobic fermentation process has the potential to recover more resources from sludge and thus, benefit the environment.
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Affiliation(s)
- Li Liu
- Beijing Key Lab for Source Control Technology of Water Pollution, Beijing Forestry University, Beijing 100083, China; Engineering Research Center for Water Pollution Source Control & Eco-remediation, College of Environmental Science and Engineering, Beijing Forestry University, Beijing 100083, China
| | - Yu Pan
- Beijing Key Lab for Source Control Technology of Water Pollution, Beijing Forestry University, Beijing 100083, China; Engineering Research Center for Water Pollution Source Control & Eco-remediation, College of Environmental Science and Engineering, Beijing Forestry University, Beijing 100083, China
| | - Xiaohan Zhi
- Beijing Key Lab for Source Control Technology of Water Pollution, Beijing Forestry University, Beijing 100083, China; Engineering Research Center for Water Pollution Source Control & Eco-remediation, College of Environmental Science and Engineering, Beijing Forestry University, Beijing 100083, China
| | - Long Chen
- Beijing Key Lab for Source Control Technology of Water Pollution, Beijing Forestry University, Beijing 100083, China; Engineering Research Center for Water Pollution Source Control & Eco-remediation, College of Environmental Science and Engineering, Beijing Forestry University, Beijing 100083, China
| | - Hongtao Zhu
- Beijing Key Lab for Source Control Technology of Water Pollution, Beijing Forestry University, Beijing 100083, China; Engineering Research Center for Water Pollution Source Control & Eco-remediation, College of Environmental Science and Engineering, Beijing Forestry University, Beijing 100083, China.
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15
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Shi M, Liu H, Zhang X, Li Y, Huang F, Zhao C, Guo J, Wu P, Liu H. A neglected contributor of thermal hydrolysis to sludge anaerobic digestion: Fulvic acids release and their influences. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2023; 343:118217. [PMID: 37229867 DOI: 10.1016/j.jenvman.2023.118217] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/17/2023] [Revised: 05/17/2023] [Accepted: 05/19/2023] [Indexed: 05/27/2023]
Abstract
Fulvic acids (FAs) belong to inert organic matters in sewage sludge and their influences are often overlooked during convectional anaerobic digestion (AD). Currently, thermal hydrolysis (TH) has been widely applied on sludge pretreatment before AD processes, which makes FAs undergo drastic evolutions and aggressive to sludge AD. Results in the present study indicated that FAs concentration in the liquid was elevated by over incredible 150 folds during sludge TH, from 3.4 mg/L in raw sludge to 590.0 mg/L in hydrolyzed sludge at 180 °C. Moreover, during sludge TH, the chemical structures of FAs, including aromatic condensation degree, elemental composition and functional group, also underwent significant changes, which enhanced FAs electron transfer capability, reduced their biodegradability and promoted their roles on sludge AD. Furthermore, fortunately, the evolutions of FAs were favorable to sludge AD in general. Methane production could be promoted by about 20% under FAs concentration of 0.6 g/L, and the FAs extracted from hydrolyzed sludge presented higher promotion performances than that of the raw FAs, in which 180 °C FAs were particularly conspicuous. Furthermore, FAs evolutions would present differential influences on each phase of sludge AD, promotional to acidogenesis and methanogenesis but inhibitory to hydrolysis. Pearson correlation analysis indicated FAs influences on sludge AD, particularly the hydrolysis phase, were not only related to their concentration, but also chemical structure. The findings of this study demonstrated that FAs influences should not be negligible anymore during sludge AD with TH pretreatment. Meanwhile, since FAs promotion on sludge AD was closely related to their concentration and chemical structure, it would be significant to take FAs evolutions as auxiliary indexes for the regulations of sludge TH.
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Affiliation(s)
- Mingze Shi
- Jiangsu Key Laboratory of Anaerobic Biotechnology, School of Environment and Civil Engineering, Jiangnan University, Wuxi, 214122, Jiangsu Province, PR China
| | - Hongbo Liu
- Jiangsu Key Laboratory of Anaerobic Biotechnology, School of Environment and Civil Engineering, Jiangnan University, Wuxi, 214122, Jiangsu Province, PR China; Jiangsu Collaborative Innovation Center of Technology and Material of Water Treatment, Suzhou University of Science and Technology, Suzhou, 215011, Jiangsu Province, PR China.
| | - Xuedong Zhang
- Jiangsu Key Laboratory of Anaerobic Biotechnology, School of Environment and Civil Engineering, Jiangnan University, Wuxi, 214122, Jiangsu Province, PR China
| | - Yajie Li
- Jiangsu Collaborative Innovation Center of Technology and Material of Water Treatment, Suzhou University of Science and Technology, Suzhou, 215011, Jiangsu Province, PR China
| | - Fang Huang
- Jiangsu Key Laboratory of Anaerobic Biotechnology, School of Environment and Civil Engineering, Jiangnan University, Wuxi, 214122, Jiangsu Province, PR China
| | - Cheng Zhao
- Jiangsu Key Laboratory of Anaerobic Biotechnology, School of Environment and Civil Engineering, Jiangnan University, Wuxi, 214122, Jiangsu Province, PR China
| | - Jun Guo
- Jiangsu Key Laboratory of Anaerobic Biotechnology, School of Environment and Civil Engineering, Jiangnan University, Wuxi, 214122, Jiangsu Province, PR China
| | - Ping Wu
- Jiangsu Key Laboratory of Anaerobic Biotechnology, School of Environment and Civil Engineering, Jiangnan University, Wuxi, 214122, Jiangsu Province, PR China
| | - He Liu
- Jiangsu Key Laboratory of Anaerobic Biotechnology, School of Environment and Civil Engineering, Jiangnan University, Wuxi, 214122, Jiangsu Province, PR China; Jiangsu Collaborative Innovation Center of Technology and Material of Water Treatment, Suzhou University of Science and Technology, Suzhou, 215011, Jiangsu Province, PR China
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16
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Castro-Fernandez A, Taboada-Santos A, Balboa S, Lema JM. Thermal hydrolysis pre-treatment has no positive influence on volatile fatty acids production from sewage sludge. BIORESOURCE TECHNOLOGY 2023; 376:128839. [PMID: 36906240 DOI: 10.1016/j.biortech.2023.128839] [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: 01/20/2023] [Revised: 02/28/2023] [Accepted: 03/04/2023] [Indexed: 06/18/2023]
Abstract
The study compares the potential to produce volatile fatty acids (VFA) from sewage sludge, both raw and thermally pre-treated in two modes of operation. In batch mode, raw sludge at pH 8 obtained the highest maximum VFA yield (0.41 g COD-VFA/g CODfed) whereas pre-treated sludge achieved a lower value (0.27 g COD-VFA/g CODfed). The operation of 5-L continuous reactors showed that thermal hydrolysis pre-treatment (THP) did not have any significant influence on VFA yields, averaging 15.1 % g COD-VFA/g COD with raw sludge and 16.6 % g COD-VFA/g COD with pre-treated one. Microbial community analysis showed that phylum Firmicutes was predominant in both reactors and that the enzymatic profiles involved in VFA production were very similar regardless of the substrate fed.
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Affiliation(s)
- Ander Castro-Fernandez
- CETAQUA, Water Technology Centre, A Vila da Auga, José Villar Granjel 33, E-15890, Santiago de Compostela, Spain; CRETUS Institute, Department of Chemical Engineering, School of Engineering, Universidade de Santiago de Compostela, E-15782, Santiago de Compostela, Spain.
| | - Anton Taboada-Santos
- CETAQUA, Water Technology Centre, A Vila da Auga, José Villar Granjel 33, E-15890, Santiago de Compostela, Spain
| | - Sabela Balboa
- CRETUS Institute, Department of Chemical Engineering, School of Engineering, Universidade de Santiago de Compostela, E-15782, Santiago de Compostela, Spain
| | - Juan M Lema
- CRETUS Institute, Department of Chemical Engineering, School of Engineering, Universidade de Santiago de Compostela, E-15782, Santiago de Compostela, Spain
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17
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Cui Y, Zhao B, Zhang X, Ma X, Zhou A, Wang S, Yue X, Li J, Meng J. Denitrification performance and in-situ fermentation mechanism of the wastepaper-flora slow-release carbon source. BIORESOURCE TECHNOLOGY 2023; 380:129074. [PMID: 37088430 DOI: 10.1016/j.biortech.2023.129074] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/22/2023] [Revised: 04/11/2023] [Accepted: 04/18/2023] [Indexed: 05/03/2023]
Abstract
Using wastepaper as external carbon sources is an optional way to achieve total nitrogen removal faced with low carbon to nitrogen ratio municipal sewage. Most of studies have primarily focused on using cellulose-rich wastes establishing the separate denitrification units to achieve in-situ fermentation, which can cause blockages and prolong the process chain. In response, a novel in-situ fermentation wastepaper-flora slow-release carbon source (IF-WF) was proposed using in the original denitrification unit. IF-WF could be efficiently utilized in situ and the denitrification rate increased with the increase of nitrate nitrogen. The fermentation products were highly available, but internal acidification of IF-WF inhibited fermentation. Moreover, IF-WF limited the growth of polysaccharides in the extracellular polymeric substances of denitrified sludge. IF-WF finally formed the structure dominated by nitrate-reduction bacteria outside and cellulose-degrading bacteria inside. These results provide guidance for understanding the mechanism of IF-WF for in-situ fermentation to promote nitrogen removal.
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Affiliation(s)
- Ying Cui
- College of Environmental Science and Engineering, Taiyuan University of Technology, Taiyuan 030024, China
| | - Bowei Zhao
- College of Environmental Science and Engineering, Taiyuan University of Technology, Taiyuan 030024, China
| | - Xiao Zhang
- College of Environmental Science and Engineering, Taiyuan University of Technology, Taiyuan 030024, China
| | - Xiao Ma
- School of Ecology, Environment and Resources, Guangdong University of Technology, Guangzhou, 510006, China
| | - Aijuan Zhou
- College of Environmental Science and Engineering, Taiyuan University of Technology, Taiyuan 030024, China
| | - Sufang Wang
- College of Environmental Science and Engineering, Taiyuan University of Technology, Taiyuan 030024, China
| | - Xiuping Yue
- College of Environmental Science and Engineering, Taiyuan University of Technology, Taiyuan 030024, China; Shanxi-Zheda Institute of Advanced Materials and Chemical Engineering, Taiyuan 030000, China.
| | - Jianzheng Li
- State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, Harbin 150090, China
| | - Jia Meng
- State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, Harbin 150090, China
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18
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Zhang L, Wang X, Chen Y, Zhang B, Xu H, Li C, Zhou Y. Medium-chain fatty acid production from thermal hydrolysed sludge without external electron donor supplementation. BIORESOURCE TECHNOLOGY 2023; 374:128805. [PMID: 36849100 DOI: 10.1016/j.biortech.2023.128805] [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: 02/11/2023] [Accepted: 02/24/2023] [Indexed: 06/18/2023]
Abstract
In this study, medium-chain fatty acid (MCFA) generation from mixed sludge (including primary sludge and waste activated sludge) was investigated without additional electron donors (EDs). 0.5 g COD/L of MCFAs was produced and the in situ generated ethanol could serve as the EDs during the anaerobic fermentation of mixed sludge without thermal hydrolysis process (THP) pretreatment. THP increased the MCFA production by approximately 128% in the anaerobic fermentation. During 102 days of operation, the fermentation of THP pre-treated mixed sludge stably generated 2.9 g COD/L MCFAs. The self-generated EDs could not maximize MCFA production, and external addition of ethanol improved MCFA yield. Caproiciproducens was the dominant chain-elongating bacteria. PICRUST2 revealed that both fatty acid biosynthesis and reverse β-oxidation pathways could participate in MCFA synthesis, and ethanol addition could enhance the contribution of the reverse β-oxidation pathway. Future studies should focus on the improvement of MCFA production from THP-assisted sludge fermentation.
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Affiliation(s)
- Liang Zhang
- Guangdong Provincial Key Lab of Environmental Pollution Control and Remediation Technology, School of Environmental Science and Engineering, Sun Yat-Sen University, Guangzhou, China
| | - Xiuping Wang
- Guangdong Provincial Key Lab of Environmental Pollution Control and Remediation Technology, School of Environmental Science and Engineering, Sun Yat-Sen University, Guangzhou, China
| | - Yun Chen
- Advanced Environmental Biotechnology Centre, Nanyang Environment and Water Research Institute, Nanyang Technological University, Singapore 637141, Singapore
| | - Baorui Zhang
- Advanced Environmental Biotechnology Centre, Nanyang Environment and Water Research Institute, Nanyang Technological University, Singapore 637141, Singapore
| | - Hui Xu
- Advanced Environmental Biotechnology Centre, Nanyang Environment and Water Research Institute, Nanyang Technological University, Singapore 637141, Singapore
| | - Chenchen Li
- Advanced Environmental Biotechnology Centre, Nanyang Environment and Water Research Institute, Nanyang Technological University, Singapore 637141, Singapore
| | - Yan Zhou
- Advanced Environmental Biotechnology Centre, Nanyang Environment and Water Research Institute, Nanyang Technological University, Singapore 637141, Singapore; School of Civil and Environmental Engineering, Nanyang Technological University, Singapore 639798, Singapore.
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19
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Wan J, Zhang L, Jia B, Yang B, Luo Z, Yang J, Boguta P, Su X. Effects of enzymes on organic matter conversion in anaerobic fermentation of sludge to produce volatile fatty acids. BIORESOURCE TECHNOLOGY 2022; 366:128227. [PMID: 36332860 DOI: 10.1016/j.biortech.2022.128227] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/22/2022] [Revised: 10/23/2022] [Accepted: 10/26/2022] [Indexed: 06/16/2023]
Abstract
Sludge hydrolysis is a vital step in anaerobic digestion of sludge. This study compared the efficacy of free versus immobilized enzymes at different concentrations in promoting sludge disintegration. Pretreatment with 1,000 mg/L immobilized enzymes was more efficient in promoting sludge disintegration than free enzymes at the same concentration. Under the optimized conditions, volatile fatty acids (VFAs) were produced at 10.6 g/L, accounting for 85 % of total soluble chemical oxygen demand. Improved VFA production was attributed to the release of large amounts of polysaccharides and proteins from the enzymatically pretreated sludge. Released organic matter are the substrates for VFAs generated by the determined microbial community of Firmicutes, Proteobacteria, Bacteroidetes, Actinobacteria, and Chloroflexi. In this study, anaerobic fermentation was used to successfully convert organic matter in sludge into high-value-added VFAs. Therefore, this process can be selected as a strategy to reduce carbon emissions from wastewater treatment plants (WWTPs).
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Affiliation(s)
- Juanjuan Wan
- School of Environment and Energy, Guangdong Provincial Key Laboratory of Solid Wastes Pollution Control and Recycling, South China University of Technology, Guangzhou, Guangdong 510006, China
| | - Lijuan Zhang
- School of Environment and Energy, Guangdong Provincial Key Laboratory of Solid Wastes Pollution Control and Recycling, South China University of Technology, Guangzhou, Guangdong 510006, China; School of Environment, South China Normal University, University Town, Guangzhou, Guangdong 510006, China
| | - Boyu Jia
- School of Environment and Energy, Guangdong Provincial Key Laboratory of Solid Wastes Pollution Control and Recycling, South China University of Technology, Guangzhou, Guangdong 510006, China
| | - Bo Yang
- School of Environment and Energy, Guangdong Provincial Key Laboratory of Solid Wastes Pollution Control and Recycling, South China University of Technology, Guangzhou, Guangdong 510006, China
| | - Zeliang Luo
- College of Electro-mechanical Engineering, Zhuhai City Polytechnic, Zhuhai, Guangdong 519090, China
| | - Jiakuan Yang
- School of Environmental Science and Engineering, Huazhong University of Science and Technology, Wuhan, Hubei 430074, China
| | - Patrycja Boguta
- Institute of Agrophysics, Polish Academy of Sciences, Doświadczalna 4, 20-290 Lublin, Poland
| | - Xintai Su
- School of Environment and Energy, Guangdong Provincial Key Laboratory of Solid Wastes Pollution Control and Recycling, South China University of Technology, Guangzhou, Guangdong 510006, China.
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