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Men Y, Li Z, Zhu L, Wang X, Cheng S, Lyu Y. New insights into membrane fouling during direct membrane filtration of municipal wastewater and fouling control with mechanical strategies. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 869:161775. [PMID: 36706998 DOI: 10.1016/j.scitotenv.2023.161775] [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: 11/23/2022] [Revised: 01/17/2023] [Accepted: 01/19/2023] [Indexed: 06/18/2023]
Abstract
Direct membrane filtration (DMF) technology achieves energy self-sufficiency through carbon recovery and utilization from municipal wastewater. To control its severe membrane fouling and improve DMF technology, targeted research on fouling behaviour and mechanisms is essential. In this study, a DMF reactor equipped with a flat-sheet ceramic membrane was conducted under three scenarios: without control, with intermittent aeration, and with periodic backwash. This system achieved efficient carbon concentration with chemical oxygen demand below 50 mg/L in permeate. Membrane fouling was dominated by intermediate blocking and cake filtration. And reversible external resistance accounted for over 85 % of total resistance. Predominant membrane foulants were free proteins, whose deposition underlies the attachment of cells and biopolymers. Backwash decreased the fouling rate and increased fouling layer porosity by indiscriminately detaching foulants from the membrane surface. While aeration enhanced the back transport of large particles and microbial activity, causing a relatively thin and dense fouling layer containing more microorganisms and β-d-glucopyranose polysaccharides, which implies a higher biofouling potential during long-term operation. In addition, aeration combined with backwash enhanced fouling control fivefold over either one alone. Therefore, simultaneous operation of backwash and other mechanical methods that can provide shear without stimulating aerobic microbial activity is a preferred strategy for minimizing membrane fouling during DMF of municipal wastewater.
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Affiliation(s)
- Yu Men
- School of Energy and Environmental Engineering, Beijing Key Laboratory of Resource-oriented Treatment of Industrial Pollutants, University of Science and Technology Beijing, Beijing 100083, PR China
| | - Zifu Li
- School of Energy and Environmental Engineering, Beijing Key Laboratory of Resource-oriented Treatment of Industrial Pollutants, University of Science and Technology Beijing, Beijing 100083, PR China; Nanjing Yanjiang Academy of Resources and Ecology Science, Nanjing 210047, PR China.
| | - Lixin Zhu
- Nanjing Yanjiang Academy of Resources and Ecology Science, Nanjing 210047, PR China
| | - Xuemei Wang
- School of Energy and Environmental Engineering, Beijing Key Laboratory of Resource-oriented Treatment of Industrial Pollutants, University of Science and Technology Beijing, Beijing 100083, PR China
| | - Shikun Cheng
- School of Energy and Environmental Engineering, Beijing Key Laboratory of Resource-oriented Treatment of Industrial Pollutants, University of Science and Technology Beijing, Beijing 100083, PR China
| | - Yaping Lyu
- School of Energy and Environmental Engineering, Beijing Key Laboratory of Resource-oriented Treatment of Industrial Pollutants, University of Science and Technology Beijing, Beijing 100083, PR China
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Sugiyama T, Ito Y, Hafuka A, Kimura K. Efficient direct membrane filtration (DMF) of municipal wastewater for carbon recovery: Application of a simple pretreatment and selection of an appropriate membrane pore size. WATER RESEARCH 2022; 221:118810. [PMID: 35834972 DOI: 10.1016/j.watres.2022.118810] [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: 04/01/2022] [Revised: 06/09/2022] [Accepted: 07/01/2022] [Indexed: 06/15/2023]
Abstract
Considerable attention has been paid in recent years to the recovery and effective utilization of organic matter in municipal wastewater for the establishment of a circular economy. Direct membrane filtration (DMF) of municipal wastewater using microfiltration (MF) or ultrafiltration (UF) membranes to retain and concentrate the organic matter in municipal wastewater could be a practical option for this purpose. However, severe membrane fouling and high concentrations of organic matter remaining in the DMF permeate are concerns to be addressed. Application of a simple pretreatment using fixed biofilms was investigated to address these issues. In this study, experiments were carried out at an existing municipal wastewater treatment plant. A moving bed biofilm reactor (MBBR) process operated under a very short HRT of 1 h and DO concentration of 0.5 mg/L selectively degraded low-molecular-weight dissolved organic matter in municipal wastewater without degradation of membrane-recoverable suspended and colloidal organic matter. Application of the pretreatment did not reduce the amount of organic carbon recovered by DMF using an MF membrane (approximately 70% of the influent COD being recovered), while it dramatically mitigated the membrane fouling probably due to the alteration of characteristics of dissolved organic matter in wastewater. The pretreatment also reduced the concentration of organic matter in the DMF permeate by 41%: COD concentration in the DMF permeate was as low as 40 mg/L. With the established MBBR pretreatment, performances of MF (0.1 µm) and UF (molecular weight cut-off: 150,000) membranes for DMF were compared in parallel. It was found that the increase of the recoverable amount of organic matter by using UF was marginal (about 5%), whereas fouling in UF was much more severe than that in MF. The severe fouling in UF was caused by inorganic colloids such as FeS that could pass through MF membranes but be retained by UF membranes. Based on the results obtained in this study, it is concluded that MF is more suitable than UF for efficient DMF.
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Affiliation(s)
- Toru Sugiyama
- Division of Environmental Engineering, Hokkaido University, N13W8, Kita-ku, Sapporo 060-8628, Japan
| | - Yui Ito
- Division of Environmental Engineering, Hokkaido University, N13W8, Kita-ku, Sapporo 060-8628, Japan
| | - Akira Hafuka
- Division of Environmental Engineering, Hokkaido University, N13W8, Kita-ku, Sapporo 060-8628, Japan
| | - Katsuki Kimura
- Division of Environmental Engineering, Hokkaido University, N13W8, Kita-ku, Sapporo 060-8628, Japan.
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Wang W, Zhang Z, Ma L, Xu X, Zhang P, Yu H. Explorations of complex thermally induced phase separation (C-TIPS) method for manufacturing novel diphenyl ether polysulfate flat microporous membranes. J Memb Sci 2022. [DOI: 10.1016/j.memsci.2022.120739] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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Tian J, Teng Y, Gao S, Zhang R. A Metal-organic composite ultrafiltration membrane synthesized via Quadratic phase inversion. Sep Purif Technol 2022. [DOI: 10.1016/j.seppur.2021.119973] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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He C, Wang K, Fang K, Gong H, Jin Z, He Q, Wang Q. Up-concentration processes of organics for municipal wastewater treatment: New trends in separation. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 787:147690. [PMID: 34004540 DOI: 10.1016/j.scitotenv.2021.147690] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/09/2021] [Revised: 05/07/2021] [Accepted: 05/07/2021] [Indexed: 06/12/2023]
Abstract
Carbon neutrality is a pressing goal for the whole society. Over 20% of municipality electrical energy on public utilities was consumed by the operation of wastewater treatment plants (WWTPs). Up-concentration of organic matters and maximum energy recovery is essential for a more sophisticated municipal wastewater management. Chemical coagulation and biological adsorption have been used to achieve efficient carbon capture, while separation is an overlooked step. It may lead to poor effluent quality, as well as consume most of the time and volume. The introduction of new driving forces, such as pressure and magnetism, significantly improved the retention rate and speed, respectively. In this paper, recent works were comprehensively reviewed and a horizontal comparison was conducted from aspects of separation speed, retention rate, concentrate characteristics and economic costs. This review also discussed the selection of technologies under different conditions. Finally, the practical application, fouling mitigation with considering the value of the concentrate, identification of unique concentrate characteristics, and the establishment of an evaluation system was suggested as core issues for future researches. This review will promote the development of an energy-efficient wastewater treatment system with up-concentration processes.
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Affiliation(s)
- Conghui He
- State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing 100084, PR China
| | - Kaijun Wang
- State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing 100084, PR China
| | - Kuo Fang
- State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing 100084, PR China.
| | - Hui Gong
- State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing 100084, PR China
| | - Zhengyu Jin
- State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing 100084, PR China
| | - Qiuhang He
- State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing 100084, PR China
| | - Qi Wang
- State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing 100084, PR China
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Jiang B, Hu B, Yang N, Zhang L, Sun Y, Xiao X. Study of Turbulence Promoters in Prolonging Membrane Life. MEMBRANES 2021; 11:268. [PMID: 33917725 PMCID: PMC8068148 DOI: 10.3390/membranes11040268] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/07/2021] [Revised: 04/02/2021] [Accepted: 04/06/2021] [Indexed: 01/06/2023]
Abstract
Nanofiltration membrane technology is an effective method for secondary treated sewage purification. However, membrane fouling, which is inevitable in the membrane-separation process, can reduce membrane performance and shorten membrane life. Installing a turbulence promoter is a promising means of improving the hydraulic conditions inside the membrane chamber. In this study, the effect of turbulence promoter on prolonging membrane life was studied for the first time. Flat-sheet polyethersulfone nanofiltration membrane was used to filter humic acid solution, used for simulating secondary treated sewage. By comparing photographs and SEM images of the membrane before and after the simulated secondary treated sewage filtration, it was found that humic acid tended to be deposited on the low-velocity region, which was reflected by COMSOL simulation. After incorporating a turbulence promoter, the reduction of the humic acid deposition area and membrane fouling resistance indicated that the turbulence promoter could reduce membrane fouling due to the improved hydraulic conditions. Additionally, the turbulence promoter also increased the flux and reduced the flux decay rate. The turbulence promoter was then place in the crossflow flat-sheet membrane filtration module, and the variation of flux with time was tested in simulated secondary treated sewage with different concentrations. The results showed that the membrane life for the filtration of simulated secondary treated sewage comprising 50, 250, and 500 ppm humic acid increased by 23.1%, 80.4%, and 85.7%, respectively. The results of this article can serve as a reference for the prediction of membrane life and the performance enhancement mechanism of membranes containing a turbulence promoter.
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Affiliation(s)
| | | | | | | | | | - Xiaoming Xiao
- School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, China; (B.J.); (B.H.); (N.Y.); (L.Z.); (Y.S.)
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