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Cui H, Zhang L, Zhang Q, Li X, Peng Y, Wang C. Enhancing nitrogen removal of carbon-limited municipal wastewater in step-feed biofilm batch reactor through integration of anammox. BIORESOURCE TECHNOLOGY 2023; 381:129091. [PMID: 37105262 DOI: 10.1016/j.biortech.2023.129091] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/15/2023] [Revised: 04/07/2023] [Accepted: 04/22/2023] [Indexed: 05/09/2023]
Abstract
The biological nitrogen removal of municipal wastewater was successfully improved by integrating anammox in a step-feed sequencing biofilm batch reactor. Despite fluctuating influent carbon to nitrogen ratio (1.9-5.1) and decreasing temperature (24.1-16.3 ℃), nitrogen removal efficiency of 95.9 ± 1.4 % and nitrogen removal rate of 0.23 ± 0.02 kg N/(m3·d) were successfully maintained without requirement of external carbon sources. The advanced removal performance was mainly attributed to the enhanced anammox. Anammox bacteria presented a high relative abundance (42.9% in biofilms, 1.5% in flocs) and anammox activity was as high as 5.42 ± 0.12 mg N/(g volatile suspended solids·h). Further analysis suggested that flexible control of influent organic and ammonium through step-feeding could provide multiple substrate supply for anammox reaction, potentially resulting in stable combination of anammox with hybrid-nitrite-shunt processes. Overall, this study provides a promising anammox-related application with simple-control step-feed strategy for enhanced and stable nitrogen removal from carbon-limited municipal wastewater.
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Affiliation(s)
- Huihui Cui
- National Engineering Laboratory for Advanced Municipal Wastewater Treatment and Reuse Technology, Engineering Research Center of Beijing, Beijing University of Technology, Beijing 100124, PR China
| | - Liang 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
| | - Qiong 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
| | - Xiyao 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
| | - Yongzhen Peng
- National Engineering Laboratory for Advanced Municipal Wastewater Treatment and Reuse Technology, Engineering Research Center of Beijing, Beijing University of Technology, Beijing 100124, PR China.
| | - Chuanxin Wang
- Guangdong Shouhui Lantian Engineering and Technology Co., Ltd., Units 01 and 04, 5/F, Xingguang Yingjing Commercial Center, 117 Shuiyin Road, Yuexiu District, Guangzhou, PR China
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Lim SJ, Son M, Ki SJ, Suh SI, Chung J. Opportunities and challenges of machine learning in bioprocesses: Categorization from different perspectives and future direction. BIORESOURCE TECHNOLOGY 2023; 370:128518. [PMID: 36565818 DOI: 10.1016/j.biortech.2022.128518] [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: 10/31/2022] [Revised: 12/15/2022] [Accepted: 12/17/2022] [Indexed: 06/17/2023]
Abstract
Recent advances in machine learning (ML) have revolutionized an extensive range of research and industry fields by successfully addressing intricate problems that cannot be resolved with conventional approaches. However, low interpretability and incompatibility make it challenging to apply ML to complicated bioprocesses, which rely on the delicate metabolic interplay among living cells. This overview attempts to delineate ML applications to bioprocess from different perspectives, and their inherent limitations (i.e., uncertainties in prediction) were then discussed with unique attempts to supplement the ML models. A clear classification can be made depending on the purpose of the ML (supervised vs unsupervised) per application, as well as on their system boundaries (engineered vs natural). Although a limited number of hybrid approaches with meaningful outcomes (e.g., improved accuracy) are available, there is still a need to further enhance the interpretability, compatibility, and user-friendliness of ML models.
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Affiliation(s)
- Seung Ji Lim
- Water Cycle Research Center, Korea Institute of Science and Technology, Seoul 02792, Republic of Korea
| | - Moon Son
- Water Cycle Research Center, Korea Institute of Science and Technology, Seoul 02792, Republic of Korea; Division of Energy and Environmental Technology, KIST School, Korea University of Science and Technology (UST), Seoul 02792, Republic of Korea
| | - Seo Jin Ki
- Department of Environmental Engineering, Gyeongsang National University, Jinju 52725, Republic of Korea
| | - Sang-Ik Suh
- Department of Energy System Engineering, Gyeongsang National University, Jinju 52725, Republic of Korea
| | - Jaeshik Chung
- Water Cycle Research Center, Korea Institute of Science and Technology, Seoul 02792, Republic of Korea; Division of Energy and Environmental Technology, KIST School, Korea University of Science and Technology (UST), Seoul 02792, Republic of Korea.
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Qin Q, Cheng Z, Jia H, Cui Z, Yang G, Sun M, Wang J. Assessment of hydraulic performance and fouling control caused by pulse flow in hollow fiber membrane module. AIChE J 2022. [DOI: 10.1002/aic.17580] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Qingwen Qin
- State Key Laboratory of Separation Membranes and Membrane Processes TianGong University Tianjin China
- School of Material Science and Engineering TianGong University Tianjin China
| | - Zhiyang Cheng
- State Key Laboratory of Separation Membranes and Membrane Processes TianGong University Tianjin China
- School of Material Science and Engineering TianGong University Tianjin China
| | - Hui Jia
- State Key Laboratory of Separation Membranes and Membrane Processes TianGong University Tianjin China
- School of Environmental Science and Engineering TianGong University Tianjin China
| | - Zhao Cui
- State Key Laboratory of Separation Membranes and Membrane Processes TianGong University Tianjin China
- School of Environmental Science and Engineering TianGong University Tianjin China
| | - Guang Yang
- State Key Laboratory of Separation Membranes and Membrane Processes TianGong University Tianjin China
- School of Environmental Science and Engineering Tianjin University Tianjin China
| | - Min Sun
- State Key Laboratory of Separation Membranes and Membrane Processes TianGong University Tianjin China
- School of Environmental Science and Engineering TianGong University Tianjin China
| | - Jie Wang
- State Key Laboratory of Separation Membranes and Membrane Processes TianGong University Tianjin China
- School of Environmental Science and Engineering TianGong University Tianjin China
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Siddiqui MA, Dai J, Luo Y, Chen G. Investigation of the short-term effects of extracellular polymeric substance accumulation with different backwashing strategies in an anaerobic self-forming dynamic membrane bioreactor. WATER RESEARCH 2020; 185:116283. [PMID: 32795719 DOI: 10.1016/j.watres.2020.116283] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/27/2020] [Revised: 08/04/2020] [Accepted: 08/05/2020] [Indexed: 06/11/2023]
Abstract
The optimum operation strategy for a side-stream external anaerobic self-forming dynamic membrane bioreactor (AnSFDMBR) was investigated by coupling such a system with an up-flow anaerobic sludge blanket reactor. Time-based backwashing with different intervals and transmembrane pressure (TMP)-based backwashing were compared as the operation strategies of the AnSFDMBR. The system performance, extracellular polymeric substance (EPS) accumulation in the dynamic layer and on the membrane mesh of the AnSFDMBR, and the physical properties of the dynamic layer were closely monitored. Both operation strategies achieved stable operation with effluent turbidity less than 5 nephelometric turbidity units with a slowly increasing TMP. However, with the time-based backwashing strategy, the EPS accumulation rate in the dynamic layer was more than 20 times higher than that on the mesh, indicating that frequent backwashing might have a negative impact on the AnSFDMBR. The impacts of EPS accumulation on the membrane mesh were negligible considering the small amount of EPS residual and the large pore size of the mesh. On the contrary, the EPS accumulation in the dynamic layer changed the layer's physical properties and further impacted on the performance of the AnSFDMBR. The accumulation of polysaccharides in the dynamic layer was the main reason for the layer's compactness, which was negatively correlated with the specific surface area and further led to the TMP increase. The polysaccharides in the dynamic layer-to-sludge ratio increased to around 1.6 with only 5 days of time-base operation. With TMP-based operation, it took more than 10 days for polysaccharides in the dynamic layer-to-sludge ratio reaching 1.6. The low TMP increase rate, high effluent quality, and slow EPS accumulation with TMP-based backwashing indicated TMP-based operation is applicable in the studied AnSFDMBR. Nevertheless, the correlation between TMP and the accumulation of polysaccharides should be further investigated to find the optimum TMP for backwashing.
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Affiliation(s)
- Muhammad Ahmar Siddiqui
- Department of Civil and Environmental Engineering, Water Technology Center, Hong Kong Branch of Chinese National Engineering Research Center for Control & Treatment of Heavy Metal Pollution, The Hong Kong University of Science & Technology, Clear Water Bay, Kowloon, Hong Kong, China
| | - Ji Dai
- Department of Civil and Environmental Engineering, Water Technology Center, Hong Kong Branch of Chinese National Engineering Research Center for Control & Treatment of Heavy Metal Pollution, The Hong Kong University of Science & Technology, Clear Water Bay, Kowloon, Hong Kong, China.
| | - Yu Luo
- Department of Civil and Environmental Engineering, Water Technology Center, Hong Kong Branch of Chinese National Engineering Research Center for Control & Treatment of Heavy Metal Pollution, The Hong Kong University of Science & Technology, Clear Water Bay, Kowloon, Hong Kong, China
| | - Guanghao Chen
- Department of Civil and Environmental Engineering, Water Technology Center, Hong Kong Branch of Chinese National Engineering Research Center for Control & Treatment of Heavy Metal Pollution, The Hong Kong University of Science & Technology, Clear Water Bay, Kowloon, Hong Kong, China
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Optimization of In Situ Backwashing Frequency for Stable Operation of Anaerobic Ceramic Membrane Bioreactor. Processes (Basel) 2020. [DOI: 10.3390/pr8050545] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
The cost-effective and stable operation of an anaerobic ceramic membrane bioreactor (AnCMBR) depends on operational strategies to minimize membrane fouling. A novel strategy for backwashing, filtration and relaxation was optimized for stable operation of a side stream tubular AnCMBR treating domestic wastewater at the ambient temperature. Two in situ backwashing schemes (once a day at 60 s/day, and twice a day at 60 s × 2/day) maintaining 55 min filtration and 5 min relaxation as a constant were compared. A flux level over 70% of the initial membrane flux was stabilized by in situ permeate backwashing irrespective of its frequency. The in situ backwashing by permeate once a day was better for energy saving, stable membrane filtration and less permeate consumption. Ex situ chemical cleaning after 60 days’ operation was carried out using pure water, sodium hypochlorite (NaOCl), and citric acid as the order. The dominant cake layer was effectively reduced by in situ backwashing, and the major organic foulants were fulvic acid-like substances and humic acid-like substances. Proteobacteria, Firmucutes, Epsilonbacteria and Bacteroides were the major microbes attached to the ceramic membrane fouling layer which were effectively removed by NaOCl.
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Cui Z, Wang J, Zhang H, Song L, Jia H, Yang G, Gao F. Influence of selective permeation of backwashing solution on the cleaning effectiveness in hollow fiber system. J Memb Sci 2018. [DOI: 10.1016/j.memsci.2017.10.010] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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Cui Z, Wang J, Zhang H, Jia H. Influence of released air on effective backwashing length in dead-end hollow fiber membrane system. J Memb Sci 2017. [DOI: 10.1016/j.memsci.2017.02.014] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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