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Jiang T, Li X, Yang J, Wang L, Wang W, Zhang L, Wang B. Potential of free nitrous acid (FNA) for sludge treatment and resource recovery from waste activated sludge: A review. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2024; 360:121170. [PMID: 38749134 DOI: 10.1016/j.jenvman.2024.121170] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/27/2023] [Revised: 04/18/2024] [Accepted: 05/11/2024] [Indexed: 06/05/2024]
Abstract
The escalating production of waste activated sludge (WAS) presents significant challenges to wastewater treatment plants (WWTPs). Free nitrous acid (FNA), known for its biocidal effect, has gained a growing focus on sludge dewatering, sludge reduction, and resource recovery from WAS due to its eco-friendly and cost-effective properties. Nevertheless, there have been no attempts made to systematically summarize or critically analyze the application of FNA in enhancing treatment and resource utilization of sludge. In this paper, we provided an overview of the current understanding regarding the application potential and influencing factors of FNA in sludge treatment, with a specific focus on enhancing sludge dewatering efficiency and reducing volume. To foster resource development from sludge, various techniques based on FNA have recently been proposed, which were comprehensively reviewed with the corresponding mechanisms meticulously discussed. The results showed that the chemical oxidation and interaction with microorganisms of FNA played the core role in improving resource utilization. Furthermore, current challenges and future prospects of the FNA-based applications were outlined. It is expected that this review can refine the theoretical framework of FNA-based processes, providing a theoretical foundation and technical guidance for the large-scale demonstration of FNA.
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Affiliation(s)
- Tan Jiang
- National Engineering Laboratory for Advanced Municipal Wastewater Treatment and Reuse Technology, Engineering Research Center of Beijing, Beijing University of Technology, Beijing 100124, PR China
| | - Xiaodi Li
- National Engineering Laboratory for Advanced Municipal Wastewater Treatment and Reuse Technology, Engineering Research Center of Beijing, Beijing University of Technology, Beijing 100124, PR China
| | - Jiayi Yang
- National Engineering Laboratory for Advanced Municipal Wastewater Treatment and Reuse Technology, Engineering Research Center of Beijing, Beijing University of Technology, Beijing 100124, PR China
| | - Lu Wang
- National Engineering Laboratory for Advanced Municipal Wastewater Treatment and Reuse Technology, Engineering Research Center of Beijing, Beijing University of Technology, Beijing 100124, PR China
| | - Wen Wang
- National Engineering Laboratory for Advanced Municipal Wastewater Treatment and Reuse Technology, Engineering Research Center of Beijing, Beijing University of Technology, Beijing 100124, PR China
| | - Li Zhang
- National Engineering Laboratory for Advanced Municipal Wastewater Treatment and Reuse Technology, Engineering Research Center of Beijing, Beijing University of Technology, Beijing 100124, PR China
| | - Bo Wang
- National Engineering Laboratory for Advanced Municipal Wastewater Treatment and Reuse Technology, Engineering Research Center of Beijing, Beijing University of Technology, Beijing 100124, PR China.
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2
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Cheng B, Zhang D, Lin Q, Zhou L, Jiang J, Bi X, Jiang W, Zan F, Wang Z, Chen G, Guo G. Thiosulfate/FeCl 3 pre-treatment enhances short-chain fatty acid production and mitigates H 2S generation during anaerobic fermentation of waste activated sludge: Performance, microbial community and ecological analyses. BIORESOURCE TECHNOLOGY 2024; 398:130548. [PMID: 38458263 DOI: 10.1016/j.biortech.2024.130548] [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: 02/14/2024] [Revised: 03/04/2024] [Accepted: 03/05/2024] [Indexed: 03/10/2024]
Abstract
Anaerobic fermentation (AF) has been identified as a promising method of transforming waste activated sludge (WAS) into high-value products (e.g., short-chain fatty acids (SCFAs)). This study developed thiosulfate/FeCl3 pre-treatment and investigated the effects of different thiosulfate/FeCl3 ratios (S:Fe = 3:1, 3:2, 1:1, 3:4 and 3:5) on SCFA production and sulfur transformation during the AF of WAS. At a S:Fe ratio of 1:1, the maximal SCFA yield (933.3 mg COD/L) and efficient H2S removal (96.5 %) were obtained. S:Fe ratios ≤ 1:1 not only benefited hydrolysis and acidification but largely mitigated H2S generation. These results were supported by the enriched acidogens and reduced sulfur-reducing bacteria (SRB). Molecular ecological network analysis further revealed that the keystone taxon (g_Saccharimonadales) was found in S:Fe = 1:1, together with reductions in associations among methanogens, acidogens and SRB. This work provides a strategy for enhancing high-value product recovery from WAS and minimising H2S emissions.
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Affiliation(s)
- Boyi Cheng
- School of Environmental Science and Engineering, Huazhong University of Science and Technology (HUST), Hubei Key Laboratory of Multi-media Pollution Cooperative Control in Yangtze Basin, Wuhan 430074, China
| | - Da Zhang
- School of Environmental Science and Engineering, Huazhong University of Science and Technology (HUST), Hubei Key Laboratory of Multi-media Pollution Cooperative Control in Yangtze Basin, Wuhan 430074, China
| | - Qingshan Lin
- College of Chemistry and Environmental Engineering, Chongqing University of Arts and Sciences, Chongqing Key Laboratory for Resource Utilization of Heavy Metal Wastewater, Yongchuan 402160, China
| | - Lichang Zhou
- School of Environmental Science and Engineering, Huazhong University of Science and Technology (HUST), Hubei Key Laboratory of Multi-media Pollution Cooperative Control in Yangtze Basin, Wuhan 430074, China
| | - Jinqi Jiang
- School of Environmental Science and Engineering, Huazhong University of Science and Technology (HUST), Hubei Key Laboratory of Multi-media Pollution Cooperative Control in Yangtze Basin, Wuhan 430074, China
| | - Xinqi Bi
- School of Environmental Science and Engineering, Huazhong University of Science and Technology (HUST), Hubei Key Laboratory of Multi-media Pollution Cooperative Control in Yangtze Basin, Wuhan 430074, China
| | - Wei Jiang
- School of Environmental Science and Engineering, Huazhong University of Science and Technology (HUST), Hubei Key Laboratory of Multi-media Pollution Cooperative Control in Yangtze Basin, Wuhan 430074, China
| | - Feixiang Zan
- School of Environmental Science and Engineering, Huazhong University of Science and Technology (HUST), Hubei Key Laboratory of Multi-media Pollution Cooperative Control in Yangtze Basin, Wuhan 430074, China
| | - Zongping Wang
- School of Environmental Science and Engineering, Huazhong University of Science and Technology (HUST), Hubei Key Laboratory of Multi-media Pollution Cooperative Control in Yangtze Basin, Wuhan 430074, China
| | - Guanghao Chen
- Department of Civil & Environmental Engineering and Hong Kong Branch of the Chinese National Engineering Research Center for Control & Treatment of Heavy Metal Pollution, The Hong Kong University of Science and Technology, Hong Kong, China
| | - Gang Guo
- School of Environmental Science and Engineering, Huazhong University of Science and Technology (HUST), Hubei Key Laboratory of Multi-media Pollution Cooperative Control in Yangtze Basin, Wuhan 430074, China.
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3
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Silva CD, Peces M, Jaques A, Muñoz JJ, Dosta J, Astals S. Fractional calculus as a generalized kinetic model for biochemical methane potential tests. BIORESOURCE TECHNOLOGY 2024; 396:130412. [PMID: 38310977 DOI: 10.1016/j.biortech.2024.130412] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/04/2023] [Revised: 01/29/2024] [Accepted: 01/30/2024] [Indexed: 02/06/2024]
Abstract
This study presents a fractional calculus model as a generalized kinetic model for estimating the maximum methane yield and degradation kinetics in biomethane potential (BMP) assays, a key analytical method in anaerobic digestion research and application. The fractional model outperformed common first-order kinetic models by yielding superior data fitting and properly managing substrate heterogeneity. The fractional model showed robust performance in mono-digestion, co-digestion and pre-treatment BMP assays with or without presence of large tailing or sigmoidal patterns in the BMP curve. The main advantage of the fractional model over other models is its ability to capture the complexities of the methane production process without losing model accuracy. Assessment of the mathematical model revealed that for fractional orders greater than 0.8 the Mittag-Leffler sequence could be transformed into a more computationally efficient exponential function.
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Affiliation(s)
- C Da Silva
- Department of Chemical Engineering and Analytical Chemistry, University of Barcelona, 08028 Barcelona, Spain; Department of Mathematics, Lab. De Càlcul Numèric (LaCàN), Universitat Politècnica de Catalunya, 08034 Barcelona, Spain.
| | - M Peces
- Department of Chemical Engineering and Analytical Chemistry, University of Barcelona, 08028 Barcelona, Spain
| | - A Jaques
- Chemical and Environmental Engineering Department, Technical University Federico Santa María, 2390123 Valparaíso, Chile
| | - J J Muñoz
- Department of Mathematics, Lab. De Càlcul Numèric (LaCàN), Universitat Politècnica de Catalunya, 08034 Barcelona, Spain; Centre International de Mètodes Numèrics en Enginyeria (CIMNE), 08034 Barcelona, Spain; Institut de Matemàtiques de la UPC - BarcelonaTech, 08028 Barcelona, Spain
| | - J Dosta
- Department of Chemical Engineering and Analytical Chemistry, University of Barcelona, 08028 Barcelona, Spain; Water Research Institute, University of Barcelona, Catalonia, 08001, Spain
| | - S Astals
- Department of Chemical Engineering and Analytical Chemistry, University of Barcelona, 08028 Barcelona, Spain
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4
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Guo H, Liu S, Wang Y, Hou J, Zhu T, Liu Y. A novel free nitrous acid (FNA)-generation pathway via ferric salts hydrolysis to mitigate sulfide and methane production in sewer: Insights into the performance and microbial mechanisms. JOURNAL OF HAZARDOUS MATERIALS 2023; 459:132284. [PMID: 37591170 DOI: 10.1016/j.jhazmat.2023.132284] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/21/2023] [Revised: 07/26/2023] [Accepted: 08/11/2023] [Indexed: 08/19/2023]
Abstract
Ferric chloride (FeCl3) served as a solid acid has attracted attention recently. However, the feasibility of FeCl3 combined with nitrite for free nitrous acid (FNA) generation in controlling sulfide and methane as well as the triggering mechanisms in the complex syntrophic consortium (i.e., sewer biofilm) remain largely unknown. This work disclosed FeCl3 as an alternative acid source could obtain comparable sulfide and methane mitigations at a low FNA dose (i.e., 0.26 mg N/L), compared to that of HCl acid source. Whereas, a faster recovery rate of sulfide production was observed using FeCl3 under a higher FNA dose (i.e., 0.81 mg N/L) despite the methane control still being comparable. The toxicological mechanisms revealed FNA reacted with proteins amide Ⅰ in extracellular polymeric substances and destroyed protein hydrogen bond. Enzymatic and genic analysis unveiled the overall suppression of hydrolysis, acidogenesis, acetogenesis, sulfidogenesis and methanogenesis steps due to the inactivation of viable cells by reactive nitrogen species. Economic and environmental assessments demonstrated that the ferric-based FNA strategy reduced chemical costs and N2O emission (ca. 26.5% decrease) compared to the traditional HCl-based FNA method. This work broadens the application of iron salt-based technology in urban water system, together with understanding the biological mechanisms of FNA-based technology.
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Affiliation(s)
- Haixiao Guo
- School of Environmental Science and Engineering, Tianjin University, Tianjin 300072, China
| | - Siru Liu
- School of Environmental Science and Engineering, Tianjin University, Tianjin 300072, China
| | - Yufen Wang
- School of Environmental Science and Engineering, Tianjin University, Tianjin 300072, China
| | - Jiaqi Hou
- School of Environmental Science and Engineering, Tianjin University, Tianjin 300072, China
| | - Tingting Zhu
- School of Environmental Science and Engineering, Tianjin University, Tianjin 300072, China
| | - Yiwen Liu
- School of Environmental Science and Engineering, Tianjin University, Tianjin 300072, China.
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5
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Paranjpe A, Saxena S, Jain P. A Review on Performance Improvement of Anaerobic Digestion Using Co-Digestion of Food Waste and Sewage Sludge. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2023; 338:117733. [PMID: 37004482 DOI: 10.1016/j.jenvman.2023.117733] [Citation(s) in RCA: 11] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/01/2022] [Revised: 03/09/2023] [Accepted: 03/10/2023] [Indexed: 06/19/2023]
Abstract
Anaerobic co-digestion (AcoD) is a vital technology in the decarburization of the economy because of its ability to process organic waste, recover nutrients, and create biogas as a sustainable biofuel all at the same time. This attribute also makes this technology a viable partner in pursuing a circular economic model. However, the poor biogas output of typical substrates like sewage sludge and animal manure and the hefty installation costs limit its viability. This review paper with literature analysis provides a good grasp of the anaerobic co-digesting process with diverse food digestion methods. In this survey, we have analyzed the Anaerobic Digestion of water waste, food waste, and animal manure and the anaerobic co-digestion of animal waste with water waste and food waste with water waste. This analysis demonstrates that anaerobic co-digestion produces more methane biogas than anaerobic digestion. Also, it has been shown that by adjusting the ratio of food and animal waste to water waste, we can produce more methane. In the future, we would like to supplement anaerobic co-digestion by altering the proportion of different wastes that are mixed with water waste in order to increase methane production.
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Affiliation(s)
- Archana Paranjpe
- University Institute of Technology, Rajiv Gandhi Prodyogiki Vishwavidhyalaya, Bhopal, 462033, India.
| | - Seema Saxena
- University Institute of Technology, Rajiv Gandhi Prodyogiki Vishwavidhyalaya, Bhopal, 462033, India.
| | - Pankaj Jain
- School of Energy and Environmental Management,(UTD), Rajiv Gandhi Prodyogiki Vishwavidhyalaya, Bhopal, 462033, India.
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6
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Jiang W, Tao J, Luo J, Xie W, Zhou X, Cheng B, Guo G, Ngo HH, Guo W, Cai H, Ye Y, Chen Y, Pozdnyakov IP. Pilot-scale two-phase anaerobic digestion of deoiled food waste and waste activated sludge: Effects of mixing ratios and functional analysis. CHEMOSPHERE 2023; 329:138653. [PMID: 37044139 DOI: 10.1016/j.chemosphere.2023.138653] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/28/2022] [Revised: 02/22/2023] [Accepted: 04/08/2023] [Indexed: 05/03/2023]
Abstract
Anaerobic co-digestion of deoiled food waste (dFW) and waste activated sludge (WAS) can address the challenges derived from mono-digestion of FW. In the present study, a pilot-scale methanogenic bioreactor of a two-phase anaerobic digestion system was developed to explore the impact of dFW/WAS volatile solids ratios on the overall performance, microbial community, and metabolic pathways. Besides, the tech-economic of the system was analyzed. The results showed that the degradation efficiency of soluble chemical oxygen demand (SCOD) was more than 84.90% for all the dFW/WAS ratios (v/v) (1:0, 39:1, 29:1, 19:1 and 9:1). Moreover, the dominant genus of bacteria and archaea with different ratios were Lactobacillus (66.84-98.44%) and Methanosaeta (53.66-80.09%), respectively. Co-digestion of dFW and WAS (29: 1 in v/v ratios) obtained the highest yield of methane (0.41 L CH4/Ladded) with approximately 90% of SCOD being removed. In the pilot-scale experiment, the co-digestion of FW and WAS makes positive contribution to reusing solid waste for improving solid management.
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Affiliation(s)
- Wei Jiang
- School of Environmental Science and Engineering, Huazhong University of Science and Technology, No. 1037 Luoyu Road, Wuhan, 430074, China
| | - Jiale Tao
- School of Environmental Science and Engineering, Huazhong University of Science and Technology, No. 1037 Luoyu Road, Wuhan, 430074, China
| | - Jiwu Luo
- Central South Design and Research Institute of China Municipal Engineering Co., Ltd., Wuhan, Hubei, 430014, China
| | - Wengang Xie
- Central South Design and Research Institute of China Municipal Engineering Co., Ltd., Wuhan, Hubei, 430014, China
| | - Xiaojuan Zhou
- Central South Design and Research Institute of China Municipal Engineering Co., Ltd., Wuhan, Hubei, 430014, China
| | - Boyi Cheng
- School of Environmental Science and Engineering, Huazhong University of Science and Technology, No. 1037 Luoyu Road, Wuhan, 430074, China
| | - Gang Guo
- School of Environmental Science and Engineering, Huazhong University of Science and Technology, No. 1037 Luoyu Road, Wuhan, 430074, China
| | - Huu Hao Ngo
- Centre for Technology in Water and Wastewater, School of Civil and Environmental Engineering, University of Technology Sydney, Sydney, NSW, 2007, Australia
| | - Wenshan Guo
- Centre for Technology in Water and Wastewater, School of Civil and Environmental Engineering, University of Technology Sydney, Sydney, NSW, 2007, Australia
| | - Hui Cai
- School of Environmental Science and Engineering, Huazhong University of Science and Technology, No. 1037 Luoyu Road, Wuhan, 430074, China
| | - Yuanyao Ye
- School of Environmental Science and Engineering, Huazhong University of Science and Technology, No. 1037 Luoyu Road, Wuhan, 430074, China.
| | - Yiqun Chen
- School of Civil Engineering, Wuhan University, Wuhan, 430072, China
| | - Ivan P Pozdnyakov
- V.V. Voevodsky Institute of Chemical Kinetics and Combustion, 3 Institutskaya Str., 630090, Novosibirsk, Russian Federation; Novosibirsk State University, 2 Pirogova St., 630090, Novosibirsk, Russian Federation
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7
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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.
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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.
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8
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Diaz R, Goswami A, Clark HC, Michelson R, Goel R. Volatile fatty acid production from primary and secondary sludges to support efficient nutrient management. CHEMOSPHERE 2023:138984. [PMID: 37315862 DOI: 10.1016/j.chemosphere.2023.138984] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/05/2023] [Revised: 05/16/2023] [Accepted: 05/17/2023] [Indexed: 06/16/2023]
Abstract
Enhanced hydrolysis of sludges during fermentation is an important factor to achieve solubilization of complex carbon sources and increase the amount of soluble COD that microorganisms could use as food during biological nutrient removal processes. This research shows that a combination of mixing, bioaugmentation, and co-fermentation can be used to increase the hydrolysis of sludges and enhanced the production of volatile fatty acids (VFA). Mixing of primary sludge (PS) at 350 revolutions per minute (RPM) during fermentation increased the hydrolysis of the sludge and increased the soluble chemical oxygen demand (sCOD) by 72% compared to no mixing. Mixing also increased the production of VFA by 60% compared to no mixing conditions. PS hydrolysis was also evaluated using bioaugmentation with the bacteria Bacillus amyloliquefacients, a known producer of the biosurfactant surfactin. Results showed that bioaugmentation enhanced the hydrolysis of the PS by increasing the amount of soluble carbohydrates and soluble proteins present in the form of sCOD. Methanogenesis experiments performed with co-fermentation of decanted primary sludge (PS) and raw waste-activated sludge (WAS) at 75:25 and 50:50 ratios displayed a decreased in production of total biogas by 25.58% and 20.95% and a reduction on methane production by 20.00% and 28.76% respectively, compared to co-fermentation of raw sludges. Compared to fermentation of the sludges separately, co-fermentation of PS and WAS increased the production of VFA and it was determined that 50:50 was the optimum co-fermentation ratio for production of VFA while reducing the reintroduction of nutrients produced during the fermentation process to BNR processes.
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Affiliation(s)
- Ruby Diaz
- Civil & Environmental Engineering, University of Utah, Salt Lake City, USA
| | - Anjan Goswami
- Civil & Environmental Engineering, University of Utah, Salt Lake City, USA
| | - Herald C Clark
- Civil & Environmental Engineering, University of Utah, Salt Lake City, USA
| | | | - Ramesh Goel
- Civil & Environmental Engineering, University of Utah, Salt Lake City, USA.
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9
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Hu Z, Hu S, Hong PY, Zhang X, Prodanovic V, Zhang K, Ye L, Deletic A, Yuan Z, Zheng M. Impact of electrochemically generated iron on the performance of an anaerobic wastewater treatment process. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 875:162628. [PMID: 36889383 DOI: 10.1016/j.scitotenv.2023.162628] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/13/2022] [Revised: 02/26/2023] [Accepted: 02/28/2023] [Indexed: 06/18/2023]
Abstract
Anaerobic treatment of domestic wastewater has the advantages of lower biomass yield, lower energy demand and higher energy recover over the conventional aerobic treatment process. However, the anaerobic process has the inherent issues of excessive phosphate and sulfide in effluent and superfluous H2S and CO2 in biogas. An electrochemical method allowing for in-situ generation of Fe2+ in the anode and hydroxide ion (OH-) and H2 in the cathode was proposed to overcome the challenges simultaneously. The effect of electrochemically generated iron (e‑iron) on the performance of anaerobic wastewater treatment process was explored with four different dosages in this work. The results showed that compared to control, the experimental system displayed an increase of 13.4-28.4 % in COD removal efficiency, 12.0-21.3 % in CH4 production rate, 79.8-98.5 % in dissolved sulfide reduction, 26.0-96.0 % in phosphate removal efficiency, depending on the e‑iron dosage between 40 and 200 mg Fe/L. Dosing of the e‑iron significantly upgraded the quality of produced biogas, showing a much lower CO2 and H2S contents in biogas in experimental reactor than that in control reactor. The results thus demonstrated that e‑iron can significantly improve the performance of anaerobic wastewater treatment process, bringing multiple benefits with the increase of its dosage regarding effluent and biogas quality.
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Affiliation(s)
- Zhetai Hu
- Australian Centre for Water and Environmental Biotechnology, The University of Queensland, St Lucia, QLD 4072, Australia
| | - Shihu Hu
- Australian Centre for Water and Environmental Biotechnology, The University of Queensland, St Lucia, QLD 4072, Australia
| | - Pei-Ying Hong
- Biological and Environmental Science and Engineering Division, King Abdullah University of Science and Technology (KAUST), Thuwal, SA 23955, Saudi Arabia
| | - Xueqin Zhang
- Australian Centre for Water and Environmental Biotechnology, The University of Queensland, St Lucia, QLD 4072, Australia
| | - Veljko Prodanovic
- School of Civil and Environmental Engineering, UNSW Sydney, NSW 2052, Australia
| | - Kefeng Zhang
- School of Civil and Environmental Engineering, UNSW Sydney, NSW 2052, Australia
| | - Liu Ye
- School of Chemical Engineering, The University of Queensland, St Lucia, Brisbane, QLD 4072, Australia
| | - Ana Deletic
- School of Civil and Environmental Engineering, UNSW Sydney, NSW 2052, Australia; School of Civil and Environmental Engineering, Engineering Faculty, Queensland University of Technology, QLD 4001, Australia
| | - Zhiguo Yuan
- Australian Centre for Water and Environmental Biotechnology, The University of Queensland, St Lucia, QLD 4072, Australia
| | - Min Zheng
- Australian Centre for Water and Environmental Biotechnology, The University of Queensland, St Lucia, QLD 4072, Australia.
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10
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Hu Z, Hu S, Ye L, Duan H, Wu Z, Hong PY, Yuan Z, Zheng M. Novel Use of a Ferric Salt to Enhance Mainstream Nitrogen Removal from Anaerobically Pretreated Wastewater. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2023; 57:6712-6722. [PMID: 37038903 DOI: 10.1021/acs.est.2c08325] [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: 05/03/2023]
Abstract
This study aims to demonstrate a new technology roadmap to support the ongoing paradigm shift in wastewater management from pollutant removal to resource recovery. This is achieved by developing a novel use of an iron salt (i.e., FeCl3) in an integrated anaerobic wastewater treatment and mainstream anammox process. FeCl3 was chosen to be dosed in a proposed sidestream unit rather than in a primary settler or a mainstream reactor. This causes acidification of returned activated sludge and enables stable suppression of nitrite-oxidizing bacterial activity and excess sludge reduction. A laboratory-scale system, which comprised an anaerobic baffled reactor, a continuous-flow anoxic-aerobic (A/O) reactor, and a secondary settler, was designed to treat real domestic wastewater, with the performance of the system comprehensively monitored under a steady-state condition. The experimental assessments showed that the system had good effluent quality, with total nitrogen and phosphorus concentrations of 12.6 ± 1.3 mg N/L and 0.34 ± 0.05 mg P/L, respectively. It efficiently retained phosphorus in excess sludge (0.18 ± 0.03 g P/g dry sludge), suggesting its potential for further recovery. About half of influent organic carbon was recovered in the form of bioenergy (i.e., methane). This together with low energy consumption revealed that the system could produce a net energy of about 0.11 kWh/m3-wastewater, assessed by an energy balance analysis.
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Affiliation(s)
- Zhetai Hu
- Australian Centre for Water and Environmental Biotechnology, The University of Queensland, St Lucia, QLD 4072, Australia
| | - Shihu Hu
- Australian Centre for Water and Environmental Biotechnology, The University of Queensland, St Lucia, QLD 4072, Australia
| | - Liu Ye
- School of Chemical Engineering, The University of Queensland, St Lucia, Brisbane, QLD 4072, Australia
| | - Haoran Duan
- Australian Centre for Water and Environmental Biotechnology, The University of Queensland, St Lucia, QLD 4072, Australia
| | - Ziping Wu
- School of Chemical Engineering, The University of Queensland, St Lucia, Brisbane, QLD 4072, Australia
| | - Pei-Ying Hong
- Environmental Science and Engineering, Biological and Environmental Science and Engineering Division, King Abdullah University of Science and Technology (KAUST), Thuwal 23955-6900, Saudi Arabia
| | - Zhiguo Yuan
- Australian Centre for Water and Environmental Biotechnology, The University of Queensland, St Lucia, QLD 4072, Australia
| | - Min Zheng
- Australian Centre for Water and Environmental Biotechnology, The University of Queensland, St Lucia, QLD 4072, Australia
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11
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Hu Z, Liu T, Wang Z, Meng J, Zheng M. Toward Energy Neutrality: Novel Wastewater Treatment Incorporating Acidophilic Ammonia Oxidation. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2023; 57:4522-4532. [PMID: 36897644 PMCID: PMC10035426 DOI: 10.1021/acs.est.2c06444] [Citation(s) in RCA: 28] [Impact Index Per Article: 28.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/07/2022] [Revised: 01/29/2023] [Accepted: 03/02/2023] [Indexed: 05/19/2023]
Abstract
Chemically enhanced primary treatment (CEPT) followed by partial nitritation and anammox (PN/A) and anaerobic digestion (AD) is a promising roadmap to achieve energy-neutral wastewater treatment. However, the acidification of wastewater caused by ferric hydrolysis in CEPT and how to achieve stable suppression of nitrite-oxidizing bacteria (NOB) in PN/A challenge this paradigm in practice. This study proposes a novel wastewater treatment scheme to overcome these challenges. Results showed that, by dosing FeCl3 at 50 mg Fe/L, the CEPT process removed 61.8% of COD and 90.1% of phosphate and reduced the alkalinity as well. Feeding by low alkalinity wastewater, stable nitrite accumulation was achieved in an aerobic reactor operated at pH 4.35 aided by a novel acid-tolerant ammonium-oxidizing bacteria (AOB), namely, Candidatus Nitrosoglobus. After polishing in a following anoxic reactor (anammox), a satisfactory effluent, containing COD at 41.9 ± 11.2 mg/L, total nitrogen at 5.1 ± 1.8 mg N/L, and phosphate at 0.3 ± 0.2 mg P/L, was achieved. Moreover, the stable performances of this integration were well maintained at an operating temperature of 12 °C, and 10 investigated micropollutants were removed from the wastewater. An energy balance assessment indicated that the integrated system could achieve energy self-sufficiency in domestic wastewater treatment.
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Affiliation(s)
- Zhetai Hu
- Australian
Centre for Water and Environmental Biotechnology, The University of Queensland, St. Lucia 4072, Queensland, Australia
| | - Tao Liu
- Australian
Centre for Water and Environmental Biotechnology, The University of Queensland, St. Lucia 4072, Queensland, Australia
| | - Zhiyao Wang
- Australian
Centre for Water and Environmental Biotechnology, The University of Queensland, St. Lucia 4072, Queensland, Australia
| | - Jia Meng
- State
Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, 73 Huanghe Road, Harbin 150090, China
| | - Min Zheng
- Australian
Centre for Water and Environmental Biotechnology, The University of Queensland, St. Lucia 4072, Queensland, Australia
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12
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Hu Z, Li W, Duan H, Huang X, Meng J, Yang L, Zheng M. An integrated approach to vivianite recovery from waste activated sludge. BIORESOURCE TECHNOLOGY 2023; 371:128608. [PMID: 36640822 DOI: 10.1016/j.biortech.2023.128608] [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: 12/19/2022] [Revised: 01/07/2023] [Accepted: 01/09/2023] [Indexed: 06/17/2023]
Abstract
The waste activated sludge (WAS) of wastewater treatment system is often rich in phosphorus (P), which is a basic element of human life and could use up in the near future. This study proposed an integrated approach to efficiently recover P as vivianite from WAS and simultaneously enhance the sludge dewaterability. The raw WAS was first acidified using FeCl3, which was then fed to anaerobic fermenter for Fe3+ reduction. After fermentation, a technology named acid-elutriation was introduced to convert Fe and P from solid phase to liquid phase and concomitantly enhance the liquor-solid separation. Finally, vivianite was obtained via sludge eluate neutralization. The enhanced sludge dewaterability not only increases the recovery efficiency of Fe and P but also decreases the cost of sludge disposal.
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Affiliation(s)
- Zhetai Hu
- Australian Centre for Water and Environmental Biotechnology, The University of Queensland, St Lucia, QLD 4072, Australia
| | - Weiwei Li
- Australian Centre for Water and Environmental Biotechnology, The University of Queensland, St Lucia, QLD 4072, Australia
| | - Haoran Duan
- Australian Centre for Water and Environmental Biotechnology, The University of Queensland, St Lucia, QLD 4072, Australia
| | - Xin Huang
- Australian Centre for Water and Environmental Biotechnology, The University of Queensland, St Lucia, QLD 4072, Australia
| | - Jia Meng
- State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, 73 Huanghe Road, Harbin 150090, China
| | - Liangzhen Yang
- 2005 Pioneer Park, Longcheng Residential Street, Shenzhen Tongdao Environmental Technology Co., Ltd, Shenzhen 518001, China
| | - Min Zheng
- Australian Centre for Water and Environmental Biotechnology, The University of Queensland, St Lucia, QLD 4072, Australia.
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13
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Hu Z, Zheng M, Hu S, Hong PY, Zhang X, Prodanovic V, Zhang K, Pikaar I, Ye L, Deletic A, Yuan Z. Electrochemical iron production to enhance anaerobic membrane treatment of wastewater. WATER RESEARCH 2022; 225:119202. [PMID: 36215837 DOI: 10.1016/j.watres.2022.119202] [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: 08/15/2022] [Revised: 10/01/2022] [Accepted: 10/03/2022] [Indexed: 06/16/2023]
Abstract
Although iron salts such as iron(III) chloride (FeCl3) have widespread application in wastewater treatment, safety concerns limit their use, due to the corrosive nature of concentrated solutions. This study demonstrates that local, electrochemical generation of iron is a viable alternative to the use of iron salts. Three laboratory systems with anaerobic membrane processes were set up to treat real wastewater; two systems used the production of either in-situ or ex-situ electrochemical iron (as Fe2+ and Fe2+(Fe3+)2O4, respectively), while the other system served as a control. These systems were operated for over one year to assess the impact of electrochemically produced iron on system performance. The results showed that dosing of electrochemical iron significantly reduced sulfide concentration in effluent and hydrogen sulfide content in biogas, and mitigated organics-based membrane fouling, all of which are critical issues inherently related to sustainability of anaerobic wastewater treatment. The electrochemical iron strategy can generate multiple benefits for wastewater management including increased removal efficiencies for total and volatile suspended solids, chemical oxygen demand and phosphorus. The rate of methane production also increased with electrochemically produced iron. Economic analysis revealed the viability of electrochemical iron with total cost reduced by one quarter to a third compared with using FeCl3. These benefits indicate that electrochemical iron dosing can greatly enhance the overall operation and performance of anaerobic membrane processes, and this particularly facilitates wastewater management in a decentralized scenario.
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Affiliation(s)
- Zhetai Hu
- Australian Centre for Water and Environmental Biotechnology, The University of Queensland, St Lucia, QLD 4072, Australia
| | - Min Zheng
- Australian Centre for Water and Environmental Biotechnology, The University of Queensland, St Lucia, QLD 4072, Australia.
| | - Shihu Hu
- Australian Centre for Water and Environmental Biotechnology, The University of Queensland, St Lucia, QLD 4072, Australia
| | - Pei-Ying Hong
- Biological and Environmental Science and Engineering Division, King Abdullah University of Science and Technology (KAUST), Thuwal, SA 23955, Saudi Arabia
| | - Xueqing Zhang
- Australian Centre for Water and Environmental Biotechnology, The University of Queensland, St Lucia, QLD 4072, Australia
| | - Veljko Prodanovic
- Water Research Centre, School of Civil and Environmental Engineering, The University of New South Wales, Sydney, NSW 2052, Australia
| | - Kefeng Zhang
- Water Research Centre, School of Civil and Environmental Engineering, The University of New South Wales, Sydney, NSW 2052, Australia
| | - Ilje Pikaar
- School of Civil Engineering, The University of Queensland, Brisbane, QLD 4072, Australia
| | - Liu Ye
- School of Chemical Engineering, The University of Queensland, St Lucia, Brisbane, QLD 4072, Australia
| | - Ana Deletic
- Water Research Centre, School of Civil and Environmental Engineering, The University of New South Wales, Sydney, NSW 2052, Australia; School of Civil and Environmental Engineering, Engineering Faculty, Queensland University of Technology, QLD 4001, Australia
| | - Zhiguo Yuan
- Australian Centre for Water and Environmental Biotechnology, The University of Queensland, St Lucia, QLD 4072, Australia
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14
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Qiao Z, Xu S, Zhang W, Shi S, Zhang W, Liu H. Potassium ferrate pretreatment promotes short chain fatty acids yield and antibiotics reduction in acidogenic fermentation of sewage sludge. J Environ Sci (China) 2022; 120:41-52. [PMID: 35623771 DOI: 10.1016/j.jes.2022.01.001] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2021] [Revised: 12/15/2021] [Accepted: 01/03/2022] [Indexed: 06/15/2023]
Abstract
During the acidogenic fermentation converting waste activated sludge (WAS) into short-chain fatty acids (SCFA), hydrolysis of complex organic polymers is a limiting step and the transformation of harmful substances (such as antibiotics) during acidogenic fermentation is unknown. In this study, potassium ferrate (K2FeO4) oxidation was used as a pretreatment strategy for WAS acidogenic fermentation to increase the hydrolysis of sludge and destruct the harmful antibiotics. Pretreatment with K2FeO4 can effectively increase the SCFA production during acidogenic fermentation and change the distribution of SCFA components. With the dosage of 0.2 g/g TS, the maximum SCFA yield was 4823 mg COD/L, which is 28.3 times that of the control group; acetic acid accounts for more than 90% of the total SCFA. The higher dosage (0.5 g/g TS) can further increase the proportion of acetic acid, but inhibit the overall performance of SCFA production. Apart from the promotion of hydrolysis and acidogenesis, K2FeO4 pretreatment can also simultaneously oxidizes and degrades part of the antibiotics in the sludge. When the dosage is 0.5 g/g TS, the degradation efficacy of antibiotics is the most significant, and the contents of ofloxacin, azithromycin, and tetracycline in the sludge are reduced by 69%, 42%, and 50%, respectively. In addition, K2FeO4 pretreatment can also promote the release of antibiotics from sludge flocs, which is conducive to the simultaneous degradation of antibiotics in the subsequent biological treatment process.
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Affiliation(s)
- Zihao Qiao
- School of Environment and Architecture, University of Shanghai for Science and Technology, Shanghai 200093, China
| | - Suyun Xu
- School of Environment and Architecture, University of Shanghai for Science and Technology, Shanghai 200093, China.
| | - Wanqiu Zhang
- Centillion Resource Recycling (Wuxi) Co. Ltd., Wuxi 214000, China
| | - Shuyin Shi
- School of Environment and Architecture, University of Shanghai for Science and Technology, Shanghai 200093, China
| | - Wei Zhang
- School of Environment and Architecture, University of Shanghai for Science and Technology, Shanghai 200093, China
| | - Hongbo Liu
- School of Environment and Architecture, University of Shanghai for Science and Technology, Shanghai 200093, China.
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15
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Xu Q, Luo L, Li D, Johnravindar D, Varjani S, Wong JWC, Zhao J. Hydrochar prepared from digestate improves anaerobic co-digestion of food waste and sewage sludge: Performance, mechanisms, and implication. BIORESOURCE TECHNOLOGY 2022; 362:127765. [PMID: 35985463 DOI: 10.1016/j.biortech.2022.127765] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/27/2022] [Revised: 08/04/2022] [Accepted: 08/06/2022] [Indexed: 06/15/2023]
Abstract
This work reported a new waste functionalization and utilization method, which use digestate to prepare hydrochar to improve methane production from food waste (FW) and sewage sludge (SS). Experimental results presented that 10 g/L hydrochar obtained the cumulative methane production of 133.11 ± 1.18 mL/g volatile solids added, 26.99 % higher than that without hydrochar addition. By monitoring the conversion of model metabolic intermediates, 10 g/L hydrochar was determined to favor hydrolysis, acidogenesis and methonogenesis bio-processes involved in methane production, thus improving the degradation of solubilized organics and consumption of short-chain fatty acids (SCFAs) during the co-digestion. Microbial investigation revealed that 10 g/L hydrochar enriched the microbes relevant to methane production (e.g., Methanosaeta and Syntrophomonas), but reduced the abundances of hydrolysis- and acidogenesis-related microbes (e.g., Acinetobacter). This hydrochar-based preparation and utilization strategy might offer a novel paradigm for waste-control-waste, bringing economic and environmental benefits.
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Affiliation(s)
- Qiuxiang Xu
- Institute of Bioresource and Agriculture, Department of Biology, Hong Kong Baptist University, Kowloon Tong, Hong Kong Special Administrative Region
| | - Liwen Luo
- Institute of Bioresource and Agriculture, Department of Biology, Hong Kong Baptist University, Kowloon Tong, Hong Kong Special Administrative Region
| | - Dongyi Li
- Institute of Bioresource and Agriculture, Department of Biology, Hong Kong Baptist University, Kowloon Tong, Hong Kong Special Administrative Region
| | - Davidraj Johnravindar
- Institute of Bioresource and Agriculture, Department of Biology, Hong Kong Baptist University, Kowloon Tong, Hong Kong Special Administrative Region
| | - Sunita Varjani
- Gujarat Pollution Control Board, Gandhinagar, Gujarat 382010, India
| | - Jonathan W C Wong
- Institute of Bioresource and Agriculture, Department of Biology, Hong Kong Baptist University, Kowloon Tong, Hong Kong Special Administrative Region
| | - Jun Zhao
- Institute of Bioresource and Agriculture, Department of Biology, Hong Kong Baptist University, Kowloon Tong, Hong Kong Special Administrative Region.
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16
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Yu N, Mou A, Sun H, Liu Y. Anaerobic digestion of thickened waste activated sludge under calcium hypochlorite stress: Performance stability and microbial communities. ENVIRONMENTAL RESEARCH 2022; 212:113441. [PMID: 35561820 DOI: 10.1016/j.envres.2022.113441] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/16/2022] [Revised: 04/30/2022] [Accepted: 05/04/2022] [Indexed: 06/15/2023]
Abstract
Hypochlorite pretreatment has been proven effective in enhancing waste activated sludge (WAS) anaerobic digestion performances recently. In this study, two semi-continuous anaerobic sequencing batch reactors (ASBRs), one fed with Ca(ClO)2 pretreated thickened WAS (TWAS) and one with raw TWAS, were operated at mesophilic conditions (35 °C) for 145 days. Three loading shocks were introduced to each reactor to compare the performance stability and resilience between the digestion of Ca(ClO)2 pretreated TWAS and untreated TWAS. Microbial community shifts were quantified to reveal the microbiome responses to disturbances. The results suggested that 1% Ca(ClO)2 enhanced the digestion of TWAS by inactivating and transforming the biomass to more easily digested substrates. Co-occurrence network analysis revealed that the strongest interactions in the microbial community occurred in the steady state of TWAS anaerobic digestion.
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Affiliation(s)
- Najiaowa Yu
- Department of Civil and Environmental Engineering, University of Alberta, Edmonton, AB, T6G 1H9, Canada
| | - Anqi Mou
- Department of Civil and Environmental Engineering, University of Alberta, Edmonton, AB, T6G 1H9, Canada
| | - Huijuan Sun
- Department of Civil and Environmental Engineering, University of Alberta, Edmonton, AB, T6G 1H9, Canada
| | - Yang Liu
- Department of Civil and Environmental Engineering, University of Alberta, Edmonton, AB, T6G 1H9, Canada
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17
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Lu Y, Zhang X, Liu X, Lu Q, Li Z, Xiao J, Li Y, Hu X, Xie Q, Wang D. Ferric chloride aiding nitrite pretreatment for the enhancement of the quantity and quality of short-chain fatty acids production in waste activated sludge. WATER RESEARCH 2022; 219:118569. [PMID: 35588582 DOI: 10.1016/j.watres.2022.118569] [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: 11/11/2021] [Revised: 04/20/2022] [Accepted: 05/05/2022] [Indexed: 06/15/2023]
Abstract
The production of short-chain fatty acids (SCFAs) via anaerobic fermentation of waste activated sludge (WAS) is often limited with poor quality of SCFAs and long fermentation time. To overcome these issues, we provided an efficient strategy by using ferric chloride (FC) to aid nitrite pretreatment. Experimental results showed that the maximal SCFAs production of 211.3 ± 3.1 mg COD/g VS was achieved with 4 mmol/L of FC integrated with 250 mg/L of nitrite pretreatment on day 5, which was 4.1-fold higher than that of the blank control (52 ± 5 mg COD/g VS, day 7). Besides, the enrichment of acetic acid was observed in the combined system, which accounted for 54.6 ± 3.5% of total SCFAs, while the proportion was only 31.5 ± 4.9% in the blank control. Propionic acid, isobutyric acid, n-butyric acid, n-valeric acid and isovaleric acid accounted for 14.7 ± 1.5%, 6.9 ± 1.4%, 7.4 ± 1.5%, 13.1 ± 1.0%, and 3.3 ± 1.5% of total SCFAs in the combined system and 22.8 ± 4.0%, 11.9 ± 3.0%, 6.7 ± 3.1%, 17.6 ± 2.0%, and 9.5 ± 3.9% of total SCFAs in the blank control, respectively. It was found that soluble proteins and carbohydrates in the combined system were higher than those in the blank control, suggesting that FC and nitrite pretreatment was beneficial for WAS disintegration. The fluorescence spectrum results suggested that FC and nitrite pretreatment improved the biodegradability of released organics, which provided more biodegradable substances for the subsequent SCFAs production. This was because the addition of FC induced the formation of free nitrous acid from nitrite. Besides, FC-induced iron reduction also promoted the conversion of recalcitrant organics to biodegradable organic matter. Microbial community structure analysis demonstrated that the functional bacteria involved in acetogenesis process such as Enterococcus, Proteiniclasticum, and Petrimonas were highly enriched due to the pretreatment of FC and nitrite, indicating this method could improve the relative abundance of SCFAs producers. Overall, this study revealed that the pretreatment of FC and nitrite promoted the formation of free nitrous acid and increased the yield of SCFAs, which provided a novel method for wastewater treatment plants to ameliorate the sewage treatment craft and rationally use the existing substances in WAS to enhance resource recovery.
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Affiliation(s)
- Yue Lu
- College of Environmental Science and Engineering and Key Laboratory of Environmental Biology and Pollution Control (Ministry of Education), Hunan University, Changsha 410082, China.
| | - Xunkuo Zhang
- College of Environmental Science and Engineering and Key Laboratory of Environmental Biology and Pollution Control (Ministry of Education), Hunan University, Changsha 410082, 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, 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, China
| | - Zijing Li
- College of Environmental Science and Engineering and Key Laboratory of Environmental Biology and Pollution Control (Ministry of Education), Hunan University, Changsha 410082, China
| | - Jun Xiao
- College of Environmental Science and Engineering and Key Laboratory of Environmental Biology and Pollution Control (Ministry of Education), Hunan University, Changsha 410082, China
| | - Yifu Li
- College of Environmental Science and Engineering and Key Laboratory of Environmental Biology and Pollution Control (Ministry of Education), Hunan University, Changsha 410082, China
| | - Xingxin Hu
- College of Environmental Science and Engineering and Key Laboratory of Environmental Biology and Pollution Control (Ministry of Education), Hunan University, Changsha 410082, China
| | - Qingqing Xie
- College of Environmental Science and Engineering and Key Laboratory of Environmental Biology and Pollution Control (Ministry of Education), Hunan University, Changsha 410082, 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, China.
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18
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Tian L, Guo H, Wang Y, Su Z, Zhu T, Liu Y. Insights into Fe(Ⅱ)-sulfite-based pretreatment strategy for enhancing short-chain fatty acids (SCFAs) production from waste activated sludge: Performance and mechanism. BIORESOURCE TECHNOLOGY 2022; 353:127143. [PMID: 35427734 DOI: 10.1016/j.biortech.2022.127143] [Citation(s) in RCA: 23] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/13/2022] [Revised: 04/06/2022] [Accepted: 04/07/2022] [Indexed: 05/21/2023]
Abstract
This paper proposed a concept of "co-treating" waste activated sludge (WAS) with waste-derived sulfite and environmentally-friendly ferrous iron. The maximal short-chain fatty acids (SCFAs) production from WAS anaerobic fermentation ascended by 27.1 times after pretreated by Fe(Ⅱ) activated sulfite with a sulfite dosage of 500 mg S/L and a Fe(Ⅱ)/sulfite ratio of 1.25. Mechanism explorations elucidated that the production of SO4·- and ·OH induced by Fe(Ⅱ)-activated sulfite-auto-oxidation remarkably promoted the disintegration of WAS and the biodegradability of dissolved organic matter, leading to enrichment of substances available for SCFAs-producing microbes. Besides, activities of hydrolytic and acidogenic enzymes were stimulated, while enzymes related to SCFAs consumption were inhibited severely. Further microbial community investigation confirmed that the abundances of hydrolytic microorganisms and acidogens were enriched. In addition, sludge dewaterability and vivianite production was enhanced after Fe(Ⅱ)-sulfite pretreated WAS fermentation, thereby benefiting the subsequent sludge disposal and resource recovery.
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Affiliation(s)
- Lixin Tian
- School of Environmental Science and Engineering, Tianjin University, Tianjin 300072, PR China
| | - Haixiao Guo
- School of Environmental Science and Engineering, Tianjin University, Tianjin 300072, PR China
| | - Yufen Wang
- School of Environmental Science and Engineering, Tianjin University, Tianjin 300072, PR China
| | - Zhongxian Su
- School of Environmental Science and Engineering, Tianjin University, Tianjin 300072, PR China
| | - Tingting Zhu
- School of Environmental Science and Engineering, Tianjin University, Tianjin 300072, PR China
| | - Yiwen Liu
- School of Environmental Science and Engineering, Tianjin University, Tianjin 300072, PR China.
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19
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Meng J, Duan H, Yuan Z, Zheng M. Gravity settling and centrifugation increase the acid buffer capacity of activated sludge. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 820:153231. [PMID: 35065124 DOI: 10.1016/j.scitotenv.2022.153231] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/29/2021] [Revised: 01/13/2022] [Accepted: 01/13/2022] [Indexed: 06/14/2023]
Abstract
Buffer capacity is a critical parameter in sludge management of domestic wastewater treatment plants that determines acid/base usage. It is here shown that gravity settling or centrifugation significantly increased the buffer capacity in the supernatant of the sludge. The sludge thickening considerably elevated the total alkalinity of the sludge from 16.0 to 31.5 mgCaCO3 taking pH 5.0 for example with the sludge concentration times increasing from 2 to 20 times, while insignificantly affected the total acidity (initial 335.3 vs 240.2 mgCaCO3 at concentration times of 10 considering pH increased to 11.0). These findings indicate that the inherent buffer in sludge can be released during sludge thickening and the primary component of this buffer is alkalinity. The released buffer may be correlated to a negative surface charge inside sludge flocs, as it consumed base in titration. The increased buffer capacity in supernatant could be due to the buffer released from bound water to free water, and in particular, from the release of interstitial water, an important part of the bound water. Further mechanism analysis suggested that the increased buffer capacity in thickened sludge could relate to extracellular polymeric substances, for which more studies are needed. Overall, this study for the first time reports that sludge thickening can change the buffer capacity of sludge, affecting the efficiency and acid/base usage of sludge treatment.
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Affiliation(s)
- Jia Meng
- Australian Centre for Water and Environmental Biotechnology (ACWEB, formerly AWMC), The University of Queensland, Brisbane, QLD 4072, Australia; State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, 73 Huanghe Road, Harbin 150090, China
| | - Haoran Duan
- Australian Centre for Water and Environmental Biotechnology (ACWEB, formerly AWMC), The University of Queensland, Brisbane, QLD 4072, Australia
| | - Zhiguo Yuan
- Australian Centre for Water and Environmental Biotechnology (ACWEB, formerly AWMC), The University of Queensland, Brisbane, QLD 4072, Australia
| | - Min Zheng
- Australian Centre for Water and Environmental Biotechnology (ACWEB, formerly AWMC), The University of Queensland, Brisbane, QLD 4072, Australia.
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20
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Tang CC, Yao XY, Jin HY, Sun Q, Zou ZS, Yang WJ, He ZW, Zhou AJ, Chen F, Ren YX, Liu WZ, Wang A. Stepwise freezing-thawing treatment promotes short-chain fatty acids production from waste activated sludge. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 818:151694. [PMID: 34798085 DOI: 10.1016/j.scitotenv.2021.151694] [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: 10/09/2021] [Revised: 11/07/2021] [Accepted: 11/10/2021] [Indexed: 06/13/2023]
Abstract
Waste activated sludge (WAS), as the byproducts of wastewater treatment plants, has been greatly produced. With high cost and environmental risk of WAS disposal, to explore a low-cost and environment-friendly technology has been a great challenge. Considering that WAS is a collection of organic matters, anaerobic fermentation has been selected as a sustainable way to simultaneously recover resources and reduce environmental pollution. To recover short-chain fatty acids (SCFAs) has gained great concern because of the high value-added application and high-efficiency production process. Considering the temperature in some areas of the world can reach to below 0 °C, this study proposed an efficient strategy, i.e., stepwise freezing and thawing treatment, to promote SCFAs production. The maximal production of SCFAs, i.e., 246 mg COD/g volatile suspended solid, was obtained with the shortened retention time of five days. Mechanistic studies showed that the solubilization of both extracellular polymeric substances (EPSs) and microbial cells could be accelerated, with the EPSs removal of 58.3% for proteins and 59.0% for polysaccharides. Also, the hydrolysis process was promoted to provide more substrates for subsequent acidogenisis, and the functional microorganisms, such as Romboutsia, Paraclostridium, Macellibacteroides and Conexibacter, were greatly enriched, with a total abundance of 26.2%. Moreover, compared to control, methanogenesis was inhibited at a shortened sludge retention time (e.g., five days), which benefited to the accumulation of SCFAs, but the methane production was increased by 25.2% at a longer sludge retention time (e.g., ten days). Thus, these findings of this work may provide some new solutions for the enhanced resource recovery from WAS, and further for carbon-neutral operation of wastewater treatment plants.
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Affiliation(s)
- Cong-Cong Tang
- Shaanxi Key Laboratory of Environmental Engineering, School of Environmental and Municipal Engineering, Xi'an University of Architecture and Technology, Xi'an 710055, China; Key Laboratory of Northwest Water Resource, Environment and Ecology, Ministry of Education, Xi'an University of Architecture and Technology, Xi'an 710055, China
| | - Xing-Ye Yao
- Shaanxi Key Laboratory of Environmental Engineering, School of Environmental and Municipal Engineering, Xi'an University of Architecture and Technology, Xi'an 710055, China; Key Laboratory of Northwest Water Resource, Environment and Ecology, Ministry of Education, Xi'an University of Architecture and Technology, Xi'an 710055, China
| | - Hong-Yu Jin
- Shaanxi Key Laboratory of Environmental Engineering, School of Environmental and Municipal Engineering, Xi'an University of Architecture and Technology, Xi'an 710055, China; Key Laboratory of Northwest Water Resource, Environment and Ecology, Ministry of Education, Xi'an University of Architecture and Technology, Xi'an 710055, China
| | - Qian Sun
- Environmental Science Academy of Shaanxi Province, Xi'an 710061, China
| | - Zheng-Shuo Zou
- Shaanxi Key Laboratory of Environmental Engineering, School of Environmental and Municipal Engineering, Xi'an University of Architecture and Technology, Xi'an 710055, China; Key Laboratory of Northwest Water Resource, Environment and Ecology, Ministry of Education, Xi'an University of Architecture and Technology, Xi'an 710055, China
| | - Wen-Jing Yang
- Shaanxi Key Laboratory of Environmental Engineering, School of Environmental and Municipal Engineering, Xi'an University of Architecture and Technology, Xi'an 710055, China; Key Laboratory of Northwest Water Resource, Environment and Ecology, Ministry of Education, Xi'an University of Architecture and Technology, Xi'an 710055, China
| | - Zhang-Wei He
- Shaanxi Key Laboratory of Environmental Engineering, School of Environmental and Municipal Engineering, Xi'an University of Architecture and Technology, Xi'an 710055, China; Key Laboratory of Northwest Water Resource, Environment and Ecology, Ministry of Education, Xi'an University of Architecture and Technology, Xi'an 710055, China.
| | - Ai-Juan Zhou
- College of Environmental Science and Engineering, Taiyuan University of Technology, Taiyuan 030024, China
| | - Fan Chen
- School of Ecology and Environment, Northwestern Polytechnical University, Xi'an 710129, China
| | - Yong-Xiang Ren
- Shaanxi Key Laboratory of Environmental Engineering, School of Environmental and Municipal Engineering, Xi'an University of Architecture and Technology, Xi'an 710055, China; Key Laboratory of Northwest Water Resource, Environment and Ecology, Ministry of Education, Xi'an University of Architecture and Technology, Xi'an 710055, China
| | - Wen-Zong Liu
- Key Laboratory of Environmental Biotechnology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, 18 Shuangqing Road, Haidian District, Beijing 100085, China; School of Civil and Environmental Engineering, Harbin Institute of Technology (Shenzhen), Shenzhen 518055, China.
| | - Aijie Wang
- Key Laboratory of Environmental Biotechnology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, 18 Shuangqing Road, Haidian District, Beijing 100085, China; School of Civil and Environmental Engineering, Harbin Institute of Technology (Shenzhen), Shenzhen 518055, China
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21
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Wang Y, Zheng K, Guo H, Tong Y, Zhu T, Liu Y. Unveiling the mechanisms of how vivianite affects anaerobic digestion of waste activated sludge. BIORESOURCE TECHNOLOGY 2022; 343:126045. [PMID: 34592460 DOI: 10.1016/j.biortech.2021.126045] [Citation(s) in RCA: 22] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/23/2021] [Revised: 09/23/2021] [Accepted: 09/25/2021] [Indexed: 05/21/2023]
Abstract
Recently, phosphorus recovery as vivianite from sludge digestion system has attracted increasing attention because of its high recovery efficiency and economic value. However, the potential impact of vivianite on anaerobic digestion of waste activated sludge remains largely unknown. This study therefore aims to provide such support. Experimental results revealed that the maximal methane yield decreased from 103.55 to 76.55 mL/g volatile solids, with the vivianite level increasing from 0 to 500 mg P/L. Mechanism explorations showed that vivianite caused more substrates remaining in tightly-bound extracellular polymeric substances, and thus suppressed sludge solubilization. In addition, it was observed that hydrolysis, acidiogenesis, acetogenesis and methanogenesis bio-processes were all inhibited by vivianite. Microbial analysis revealed that vivianite significantly decreased the relative abundances of hydrolytic microbes, acidogens and methanogens. Further investigation showed that vivianite benefited sludge agglomeration and can enhance the mass transfer resistance of anaerobic digestion, further supporting the inhibitions on anaerobic digestion.
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Affiliation(s)
- Yufen Wang
- School of Environmental Science and Engineering, Tianjin University, Tianjin 300072, China
| | - Kaixin Zheng
- School of Environmental Science and Engineering, Tianjin University, Tianjin 300072, China
| | - Haixiao Guo
- School of Environmental Science and Engineering, Tianjin University, Tianjin 300072, China
| | - Yindong Tong
- School of Environmental Science and Engineering, Tianjin University, Tianjin 300072, China
| | - Tingting Zhu
- School of Environmental Science and Engineering, Tianjin University, Tianjin 300072, China
| | - Yiwen Liu
- School of Environmental Science and Engineering, Tianjin University, Tianjin 300072, China.
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22
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Guo H, Wang Y, Tian L, Wei W, Zhu T, Liu Y. Unveiling the mechanisms of a novel polyoxometalates (POMs)-based pretreatment technology for enhancing methane production from waste activated sludge. BIORESOURCE TECHNOLOGY 2021; 342:125934. [PMID: 34536839 DOI: 10.1016/j.biortech.2021.125934] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/14/2021] [Revised: 09/06/2021] [Accepted: 09/08/2021] [Indexed: 05/21/2023]
Abstract
This study proposed a novel polyoxometalates (POMs)-based pretreatment technology to improve methane production from waste activated sludge (WAS) for the first time. Experimental results indicated methane production from WAS pretreated with 0.25 g POMs/g TSS increased by 43.7%. Mechanism analysis revealed POMs pretreatment promoted WAS disintegration and improved the biodegradability of the released organics. The declined oxidation-reduction potential of digestion system provided a more favorable situation for anaerobes, and hence had positive impacts on the activity of enzymes associated with hydrolysis/acidification/methanogenesis. Model-based analysis elucidated POMs pretreatment remarkably increased both biochemical methane potential and hydrolysis rate. Microbial community analysis showed microbial community was shifted toward increase hydrolytic and acidification-associated microbes and enriched the abundance of Methanosaeta sp. This work is expected to develop an innovative technology that will simultaneously enhance energy production from WAS in the sludge treatment line and improve biological nutrient removal in the wastewater treatment line of WWTPs.
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Affiliation(s)
- Haixiao Guo
- School of Environmental Science and Engineering, Tianjin University, Tianjin 300072, China
| | - Yufen Wang
- School of Environmental Science and Engineering, Tianjin University, Tianjin 300072, China
| | - Lixin Tian
- School of Environmental Science and Engineering, Tianjin University, Tianjin 300072, China
| | - Wei Wei
- School of Environment, Harbin Institute of Technology, Harbin 150090, China
| | - Tingting Zhu
- School of Environmental Science and Engineering, Tianjin University, Tianjin 300072, China
| | - Yiwen Liu
- School of Environmental Science and Engineering, Tianjin University, Tianjin 300072, China.
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23
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Xu RZ, Fang S, Zhang L, Huang W, Shao Q, Fang F, Feng Q, Cao J, Luo J. Distribution patterns of functional microbial community in anaerobic digesters under different operational circumstances: A review. BIORESOURCE TECHNOLOGY 2021; 341:125823. [PMID: 34454239 DOI: 10.1016/j.biortech.2021.125823] [Citation(s) in RCA: 44] [Impact Index Per Article: 14.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/02/2021] [Revised: 08/16/2021] [Accepted: 08/17/2021] [Indexed: 06/13/2023]
Abstract
Anaerobic digestion (AD) processes are promising to effectively recover resources from organic wastes or wastewater. As a microbial-driven process, the functional anaerobic species played critical roles in AD. However, the lack of effective understanding of the correlations of varying microbial communities with different operational factors hinders the microbial regulation to improve the AD performance. In this paper, the main anaerobic functional microorganisms involved in different stages of AD processes were first demonstrated. Then, the response of anaerobic microbial community to different operating parameters, exogenous interfering substances and digestion substrates, as well as the digestion efficiency, were discussed. Finally, the research gaps and future directions on the understanding of functional microorganisms in AD were proposed. This review provides insightful knowledge of distribution patterns of functional microbial community in anaerobic digesters, and gives critical guidance to regulate and enrich specific functional microorganisms to accumulate certain AD products.
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Affiliation(s)
- Run-Ze Xu
- Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Ministry of Education, Hohai University, Nanjing 210098, China; College of Environment, Hohai University, Nanjing 210098, China
| | - Shiyu Fang
- Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Ministry of Education, Hohai University, Nanjing 210098, China; College of Environment, Hohai University, Nanjing 210098, China
| | - Le Zhang
- Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Ministry of Education, Hohai University, Nanjing 210098, China; College of Environment, Hohai University, Nanjing 210098, China
| | - Wenxuan Huang
- Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Ministry of Education, Hohai University, Nanjing 210098, China; College of Environment, Hohai University, Nanjing 210098, China
| | - Qianqi Shao
- Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Ministry of Education, Hohai University, Nanjing 210098, China; College of Environment, Hohai University, Nanjing 210098, China
| | - Fang Fang
- Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Ministry of Education, Hohai University, Nanjing 210098, China; College of Environment, Hohai University, Nanjing 210098, China
| | - Qian Feng
- Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Ministry of Education, Hohai University, Nanjing 210098, China; College of Environment, Hohai University, Nanjing 210098, China
| | - Jiashun Cao
- Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Ministry of Education, Hohai University, Nanjing 210098, China; College of Environment, Hohai University, Nanjing 210098, China
| | - Jingyang Luo
- Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Ministry of Education, Hohai University, Nanjing 210098, China; College of Environment, Hohai University, Nanjing 210098, China.
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24
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Calderon AG, Duan H, Seo KY, Macintosh C, Astals S, Li K, Wan J, Li H, Maulani N, Lim ZK, Yuan Z, Hu S. The origin of waste activated sludge affects the enhancement of anaerobic digestion by free nitrous acid pre-treatment. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 795:148831. [PMID: 34246135 DOI: 10.1016/j.scitotenv.2021.148831] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/12/2021] [Revised: 06/29/2021] [Accepted: 06/29/2021] [Indexed: 06/13/2023]
Abstract
Anaerobic digestion is a common stabilization method for treating primary sludge (PS) and waste activated sludge (WAS). However, its application is often limited by the degradation of WAS. Recent studies have demonstrated FNA to be an effective pre-treatment for enhancing WAS degradability, while having limited effect on PS degradability. WAS characteristics are impacted by wastewater treatment plant (WWTP) configuration and this study is the first to compare the effectiveness of FNA pre-treatment on WAS from WWTP with and without primary treatment. In this study, WAS samples were collected from four full-scale WWTPs with or without primary treatment. Sludge characterization, biomethane potential tests and mathematical modeling were conducted to assess the impacts of FNA pre-treatment on anaerobic digestion. The results showed that FNA pre-treatment was consistently effective for WAS from different WWTPs, while the extent of enhancement varied between WWTPs. For WAS from WWTPs without primary treatment, FNA pretreatment increased the rate of hydrolysis by 54-66% compared to 22-33% increase for WAS without primary treatment. In contrast, WAS from WWTPs with primary treatment experienced greater increases in methane potential (22-24%) compared to WAS from WWTPs without primary treatment (14-16%). These variances could be associated with primary treatment impacting the wastewater COD/N ratio and thus portion of extracellular polymetric substances (EPS) and cells in WAS. FNA pre-treatment targets the destruction of polymetric substances and cells, therefore WAS with a higher proportion of cells (i.e., WAS with primary treatment) experienced greater improvements in methane yield. Similarly, greater improvements in hydrolysis rate were observed for WAS from WWTP without primary sedimentation which contain higher proportions of large EPS molecules. Despite its consistent effectiveness on WAS samples, FNA pre-treatment was ineffective for improving the digestibility of high-rate activated sludge (HRAS).
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Affiliation(s)
| | - Haoran Duan
- Advanced Water Management Centre, The University of Queensland, St Lucia, QLD 4072, Australia; School of Chemical Engineering, The University of Queensland, St Lucia, QLD 4072, Australia.
| | - Kai Yee Seo
- School of Chemical Engineering, The University of Queensland, St Lucia, QLD 4072, Australia
| | | | - Sergi Astals
- Advanced Water Management Centre, The University of Queensland, St Lucia, QLD 4072, Australia; Department of Chemical Engineering and Analytical Chemistry, University of Barcelona, C/ Martí i Franquès 1, 08028 Barcelona, Spain
| | - Kaili Li
- School of Chemical Engineering, The University of Queensland, St Lucia, QLD 4072, Australia
| | - Jingjing Wan
- Advanced Water Management Centre, The University of Queensland, St Lucia, QLD 4072, Australia
| | - Huijuan Li
- Advanced Water Management Centre, The University of Queensland, St Lucia, QLD 4072, Australia
| | - Nova Maulani
- Advanced Water Management Centre, The University of Queensland, St Lucia, QLD 4072, Australia
| | - Zhuan Khai Lim
- Advanced Water Management Centre, The University of Queensland, St Lucia, QLD 4072, Australia
| | - Zhiguo Yuan
- Advanced Water Management Centre, The University of Queensland, St Lucia, QLD 4072, Australia
| | - Shihu Hu
- Advanced Water Management Centre, The University of Queensland, St Lucia, QLD 4072, Australia
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25
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Liu T, Lu Y, Zheng M, Hu S, Yuan Z, Guo J. Efficient nitrogen removal from mainstream wastewater through coupling Partial Nitritation, Anammox and Methane-dependent nitrite/nitrate reduction (PNAM). WATER RESEARCH 2021; 206:117723. [PMID: 34637975 DOI: 10.1016/j.watres.2021.117723] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/13/2021] [Revised: 08/29/2021] [Accepted: 09/26/2021] [Indexed: 06/13/2023]
Abstract
The application of partial nitritation and anammox to remove nitrogen from mainstream wastewater is of great interest because of the potential to reduce energy cost and carbon dosage. However, this process confronts a dilemma of relatively high effluent nitrogen concentration (>10 mg N/L), owning to the unwanted prevalence of nitrite-oxidizing bacteria (NOB) and the intrinsic nitrate production by anammox bacteria. Here, a novel technology, named the one-stage PNAM, that integrates Partial Nitritation, Anammox and Methane-dependent nitrite/nitrate reduction reactions, was developed in a single membrane biofilm reactor (MBfR). With feeding of synthetic mainstream wastewater containing ∼50 mg NH4+-N/L at a hydraulic retention time of 12 h, more than 95% nitrogen was removed in the established one-stage PNAM process at a practically useful rate of 0.1 kg N/m3/d. Microbial community characterization and in-situ batch tests revealed a sophisticated microbial structure consisting of ammonia-oxidizing bacteria (AOB), anammox bacteria, nitrite/nitrate-dependent anaerobic methane oxidation (n-DAMO) bacteria and archaea, and a small fraction of NOB and aerobic methanotrophs. The role of methane in removing nitrate was confirmed by switching on/off the methane supply, which relaxed the requirement for NOB suppression. In addition, the established system was relatively robust against temperature variations, evidenced by a total nitrogen removal efficiency above 80% at temperature as low as 14 ℃. The results provide a promising alternative for efficient nitrogen removal from domestic wastewater using methane as the sole carbon source.
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Affiliation(s)
- Tao Liu
- Australian Centre for Water and Environmental Biotechnology (ACWEB, formerly AWMC), The University of Queensland, St. Lucia, Queensland 4072, Australia
| | - Yan Lu
- Australian Centre for Water and Environmental Biotechnology (ACWEB, formerly AWMC), The University of Queensland, St. Lucia, Queensland 4072, Australia
| | - Min Zheng
- Australian Centre for Water and Environmental Biotechnology (ACWEB, formerly AWMC), The University of Queensland, St. Lucia, Queensland 4072, Australia
| | - Shihu Hu
- Australian Centre for Water and Environmental Biotechnology (ACWEB, formerly AWMC), The University of Queensland, St. Lucia, Queensland 4072, Australia
| | - Zhiguo Yuan
- Australian Centre for Water and Environmental Biotechnology (ACWEB, formerly AWMC), The University of Queensland, St. Lucia, Queensland 4072, Australia
| | - Jianhua Guo
- Australian Centre for Water and Environmental Biotechnology (ACWEB, formerly AWMC), The University of Queensland, St. Lucia, Queensland 4072, Australia.
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26
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Wang Z, Liu T, Duan H, Song Y, Lu X, Hu S, Yuan Z, Batstone D, Zheng M. Post-treatment options for anaerobically digested sludge: Current status and future prospect. WATER RESEARCH 2021; 205:117665. [PMID: 34547700 DOI: 10.1016/j.watres.2021.117665] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/30/2021] [Revised: 08/15/2021] [Accepted: 09/10/2021] [Indexed: 05/16/2023]
Abstract
Anaerobic digestion is the most commonly used sludge treatment technology in large-scale wastewater treatment plants (WWTPs), generating two main products, i.e., biogas and anaerobically digested (AD) sludge. Biogas can be used as a source of renewable energy, and AD sludge is often transported for agricultural land application. Land application of AD sludge is confronted with ever-increasing economic and regulatory pressures due to its high water content, high organic content and related odour and pathogen content (if poorly stabilized), as well as potential toxic metal and organic contaminants. To address these challenges, a number of technologies have been developed for the further treatment of AD sludge before final disposal. This review aims to critically evaluate these state-of-the-art technologies. These technologies were categorized based on their primary aims: 1) dewaterability enhancement; 2) solids reduction and stabilization; 3) toxic metals removal. At present, the goal of post-treatment mainly focuses on dewaterability enhancement, to reduce transport costs. In future, we propose that the post-treatment of AD sludge should orient towards multiple aims, i.e., an integrated approach enabling sludge volume reduction, stabilization (including pathogen removal), and metal solubilization simultaneously. Two promising technical routes are suggested as examples, i.e. physio-chemical iron-based advanced oxidation and biological acidic aerobic digestion, while more approaches need to be developed in future studies. We concluded that post-treatment of AD sludge will promote the AD sludge management towards a more economically favourable, socially acceptable, and environmentally sustainable way; however, further development and rigorous evaluation are required for a wider adoption.
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Affiliation(s)
- Zhiyao Wang
- Advanced Water Management Centre, The University of Queensland, St Lucia, QLD 4072, Australia
| | - Tao Liu
- Advanced Water Management Centre, The University of Queensland, St Lucia, QLD 4072, Australia
| | - Haoran Duan
- Advanced Water Management Centre, The University of Queensland, St Lucia, QLD 4072, Australia
| | - Yarong Song
- Advanced Water Management Centre, The University of Queensland, St Lucia, QLD 4072, Australia
| | - Xi Lu
- Advanced Water Management Centre, The University of Queensland, St Lucia, QLD 4072, Australia
| | - Shihu Hu
- Advanced Water Management Centre, The University of Queensland, St Lucia, QLD 4072, Australia
| | - Zhiguo Yuan
- Advanced Water Management Centre, The University of Queensland, St Lucia, QLD 4072, Australia
| | - Damien Batstone
- Advanced Water Management Centre, The University of Queensland, St Lucia, QLD 4072, Australia
| | - Min Zheng
- Advanced Water Management Centre, The University of Queensland, St Lucia, QLD 4072, Australia.
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27
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Hu Z, Duan H, Wang Z, Zhao J, Ye L, Yuan Z, Zheng M, Hu S. Centralized iron-dosing into returned sludge brings multifaceted benefits to wastewater management. WATER RESEARCH 2021; 203:117536. [PMID: 34403845 DOI: 10.1016/j.watres.2021.117536] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/23/2021] [Revised: 07/22/2021] [Accepted: 08/05/2021] [Indexed: 05/06/2023]
Abstract
Iron salts (i.e. FeCl3) are the most used chemicals in the urban wastewater system. Iron is commonly dosed into sewage or the mainstream system, which provides multiple benefits such as enhanced phosphorus removal and improved sludge settleability/dewaterability. This study reported and demonstrated a new approach that dosed FeCl3 into returned sludge in order to bring two more benefits to wastewater management: short-cut nitrogen removal via the nitrite pathway and less biomass production. This approach is achieved based on our findings that with similar amount of FeCl3, centralized iron dosing into a sidestream sludge unit generated iron concentration two orders of magnitude higher than the common mainstream dosing (e.g. 10-40 mg Fe/L-wastewater), leading to sludge acidification (pH = 2.1) with Fe (III) hydrolysis. Together with accumulated nitrite in the supernatant of the sludge, ppm-level of free nitrous acid was generated and thus enabled sludge disintegration, cell lysis, and selective elimination of nitrite-oxidizing bacteria (NOB). Long-term effects on nitrifying bacteria and overall reactor performance were evaluated using two laboratory reactor experiments for over one year. The experimental reactor showed stable nitrite accumulation with an average NO2-/(NO2- + NO3-) ratio above 80% and ∼30% observed biomass yield reduction compared to those in control reactors. In addition, the centralized sludge dosing strategy still provided benefits such as improved settleability and dewaterability of sludge and enhanced phosphorus removal.
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Affiliation(s)
- Zhetai Hu
- Advanced Water Management Centre, The University of Queensland, St Lucia QLD 4072, Australia
| | - Haoran Duan
- Advanced Water Management Centre, The University of Queensland, St Lucia QLD 4072, Australia; School of Chemical Engineering, The University of Queensland, St Lucia QLD 4072, Australia
| | - Zhiyao Wang
- Advanced Water Management Centre, The University of Queensland, St Lucia QLD 4072, Australia
| | - Jing Zhao
- Advanced Water Management Centre, The University of Queensland, St Lucia QLD 4072, Australia
| | - Liu Ye
- School of Chemical Engineering, The University of Queensland, St Lucia QLD 4072, Australia
| | - Zhiguo Yuan
- Advanced Water Management Centre, The University of Queensland, St Lucia QLD 4072, Australia
| | - Min Zheng
- Advanced Water Management Centre, The University of Queensland, St Lucia QLD 4072, Australia.
| | - Shihu Hu
- Advanced Water Management Centre, The University of Queensland, St Lucia QLD 4072, Australia
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