1
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Zhao F, Zhou Z, Du P, Li X, Lu Q. Reduction of fouling of gravity-driven membrane by combined treatment of persulphate/nanoscale zero-valent iron/ultraviolet and dynamic dual coagulant flocs layer. ENVIRONMENTAL TECHNOLOGY 2024; 45:3405-3417. [PMID: 37226802 DOI: 10.1080/09593330.2023.2215939] [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: 12/18/2022] [Accepted: 03/17/2023] [Indexed: 05/26/2023]
Abstract
In this study, persulphate and nanoscale zero-valent iron were activated by ultraviolet irradiation (PS/nZVI/UV), followed by formation of dynamic flocs with AlCl3-TiCl4 coagulant directly injected into a gravity-driven membrane (GDM) tank. Membrane fouling caused by typical organic matter fractions including humic acid (HA), HA together with bovine serum albumin (HA-BSA), HA combined with polysaccharide (HA-SA) and the HA-BSA-SA mixture at pH of 6.0, 7.5 and 9.0 were evaluated by specific flux and fouling resistance distribution. The results showed that GDM pre-layered with AlCl3-TiCl4 flocs exhibited the maximum specific flux, followed by AlCl3 and TiCl4. Pre-oxidation with 0.5 mM PS and 0.1 g nZVI under UV radiation for 20 min was beneficial to degrade HA and SA fraction with molecular weight >100 kDa and <30 kDa, and BSA fraction with <30 kDa. The presence of BSA attributed mostly to irreversible fouling, SA together with BAS could exacerbate irreversible fouling, while HA caused the least fouling. The irreversible resistance of a PS/nZVI/UV-GDM system was 62.79%, 27.27%, 58.03% and 49.68% lower than that of control GDM in the treatment of HA, HA-BSA, HA-SA and HA-BSA-SA, respectively. The PS/nZVI/UV-GDM system could achieve the highest foulants removal efficiency at pH of 6.0. Morphological observations confirmed the differences in biofouling layers in different water types. Over 30-day operation, the bacterial genera on the biofouling layer could affect the organic removals, while the type of organic matter that was present influenced the relative abundance of bacterial genera.
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Affiliation(s)
- Fuwang Zhao
- School of Energy and Environment, Zhong Yuan University of Technology, Zhengzhou, People's Republic of China
| | - Zhiwei Zhou
- College of Architecture & Civil Engineering, Faculty of Urban Construction, Beijing University of Technology, Beijing, People's Republic of China
| | - Peng Du
- College of Architecture & Civil Engineering, Faculty of Urban Construction, Beijing University of Technology, Beijing, People's Republic of China
- China Academy of Building Research, Institute of Building Fire Research, Beijing, People's Republic of China
| | - Xing Li
- College of Architecture & Civil Engineering, Faculty of Urban Construction, Beijing University of Technology, Beijing, People's Republic of China
| | - Qingxuan Lu
- School of Energy and Environment, Zhong Yuan University of Technology, Zhengzhou, People's Republic of China
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2
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Simultaneous removal of natural organic matters and copper (II) with ultrafiltration for drinking water treatment. J Memb Sci 2023. [DOI: 10.1016/j.memsci.2023.121408] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
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3
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Floc formation and growth during coagulation removing humic acid: Effect of stirring condition. Sep Purif Technol 2022. [DOI: 10.1016/j.seppur.2022.122084] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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4
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Shi W, Gao F, Li X, Wang Z. High zeolite loading mixed matrix membrane for effective removal of ammonia from surface water. WATER RESEARCH 2022; 221:118849. [PMID: 35949069 DOI: 10.1016/j.watres.2022.118849] [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: 05/11/2022] [Revised: 06/24/2022] [Accepted: 07/09/2022] [Indexed: 06/15/2023]
Abstract
While zeolite-based mixed matrix membrane (MMM) has been proven effective to remove the ammonia in the wastewater by adsorption, its adsorption capacity is limited by the low zeolite loading due to the need of a high concentration of polymer matrix to maintain the mechanical strength. To break the bottleneck, in this study we proposed a facile solvent evaporation method instead of conventional phase inversion method to prepare the zeolite-based MMMs. With this new preparation method, the loading of zeolite could reach up to ∼90wt.% while the MMM still maintained a good mechanical property. The zeolite-based MMM could treat 910 L·m-2 of feedwater before reaching the ammonia breakthrough point (0.5 mg-N·L-1) when treating the synthetic wastewater water. In addition, it showed a high rejection of turbidity and natural organic material (NOM) (∼90%), mainly due to its high negative surface charge density. When applied to treat real surface water, the membrane demonstrated a high normalized treatable capacity (∼900 L·m-2) with a high rejection to NOM (87.4%). Moreover, the MMM even showed a higher fouling resistance than the PVDF microfiltration membrane. Regeneration and cleaning with NaClO could efficiently recover the adsorption capacity and water flux of the MMM. After four cycles of operation, the MMM still maintained a high treatable capacity (850 L·m-2) with a high NOM rejection. This study provides a new strategy for the preparation of high-loading zeolite-based MMM for the effective removal of ammonia from surface water.
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Affiliation(s)
- Wei Shi
- State Key Laboratory of Pollution Control and Resource Reuse, Shanghai Institute of Pollution Control and Ecological Security, School of Environmental Science and Engineering, Tongji University, Shanghai 200092, China; Tongji Advanced Membrane Technology Center, Shanghai 200092, China
| | - Fei Gao
- State Key Laboratory of Pollution Control and Resource Reuse, Shanghai Institute of Pollution Control and Ecological Security, School of Environmental Science and Engineering, Tongji University, Shanghai 200092, China; Tongji Advanced Membrane Technology Center, Shanghai 200092, China
| | - Xuesong Li
- State Key Laboratory of Pollution Control and Resource Reuse, Shanghai Institute of Pollution Control and Ecological Security, School of Environmental Science and Engineering, Tongji University, Shanghai 200092, China; Tongji Advanced Membrane Technology Center, Shanghai 200092, China.
| | - Zhiwei Wang
- State Key Laboratory of Pollution Control and Resource Reuse, Shanghai Institute of Pollution Control and Ecological Security, School of Environmental Science and Engineering, Tongji University, Shanghai 200092, China; Tongji Advanced Membrane Technology Center, Shanghai 200092, China.
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5
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Ma B, Liu Y, Lin H, Fan H, Lu C, Zhao K, Qi J. A pilot-scale study of the integrated floc-ultrafiltration membrane-based drinking water treatment process. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 830:154809. [PMID: 35341872 DOI: 10.1016/j.scitotenv.2022.154809] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/01/2021] [Revised: 02/18/2022] [Accepted: 03/21/2022] [Indexed: 06/14/2023]
Abstract
Although applications of the integrated ultrafiltration (UF) membrane have been investigated for years, most studies have been conducted at the lab scale. Here, a case study on the integrated Fe-based floc-UF process was presented. To enhance membrane performance, both pre-filtration (bag filter) and pre-oxidation were used as pretreatments to remove particles and inhibit the development of microorganisms. Results showed that the integrated process operated stably with pre-treatments, and the UF membrane fouling behavior could be divided into three different phases: slow increase rate (phase I), medium increase rate (phase II), and fast increase rate (phase III). In comparison to those in phases II and III, both natural organic matters and colloids were the main membrane fouling mechanisms during phase I, as the pollutants were not successfully removed by flocs initially. With the continuous injection of flocs, a loose cake layer became the main fouling mechanism during phase II, resulting in the deterioration of membrane fouling. During phase III, however, microorganisms (e.g., Proteobacteria) were inevitably nourished within the cake layer and played an important role in aggravating the degree of membrane fouling. During this integrated membrane-based process, several operating factors, including floc concentration, sludge discharge frequency, and the aeration rate during backwashing, played important roles in determining membrane performance. In addition, except for oxygen consumption, all the effluent quality parameters met the drinking water criteria followed in China (GB5749-2006).
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Affiliation(s)
- Baiwen Ma
- Key Laboratory of Drinking Water Science and Technology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; Lehrstuhl für Technische Chemie II, Universität Duisburg-Essen, Essen 45117, Germany.
| | - Yansong Liu
- Key Laboratory of Drinking Water Science and Technology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; College of New Energy and Environment, Jilin University, Changchun, 130021, Jilin, China
| | - Hui Lin
- Key Laboratory of Drinking Water Science and Technology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Hongwei Fan
- College of Chemical Engineering, Beijing University of Chemical Technology, Beijing 100029, China
| | - Chaojie Lu
- Key Laboratory of Drinking Water Science and Technology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Kai Zhao
- Key Laboratory of Drinking Water Science and Technology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Jing Qi
- Key Laboratory of Drinking Water Science and Technology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
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6
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Yu J, Xu H, Wang D, Sun H, Jiao R, Liu Y, Jin Z, Zhang S. Variations in NOM during floc aging: Effect of typical Al-based coagulants and different particle sizes. WATER RESEARCH 2022; 218:118486. [PMID: 35504159 DOI: 10.1016/j.watres.2022.118486] [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: 02/10/2022] [Revised: 04/14/2022] [Accepted: 04/19/2022] [Indexed: 06/14/2023]
Abstract
Most studies on the interaction between coagulation and NOM (natural organic matter) currently focus on pollutant removal and coagulant species distribution, while studies on floc aging are lacking. Investigation onto the effects of floc aging could guide further processes that utilize flocs, such as densadeg sludge recirculation, floc predeposition for ultrafiltration, sludge condensation, and other traditional sludge reflux processes. In this study, flocs generated by Al13 and AlCl3 in microparticle- and nanoparticle-containing water were investigated, and the effect of floc aging on NOM was quantified based on several organic matter characterization techniques. Flocs absorb and release organics during aging. The flocs generated from micro-SiO2 have a significant absorbing effect for LWM-N (low-molecular-weight neutral substances) and protein-like substances, while the absorption of NOM by flocs generated from nano-SiO2 is insignificant. HS (humic substances) with high aromaticity are released during floc aging. From the molecular perspective, the molecules released during floc aging are those with higher double bond equivalents and higher aromaticity, while the absorbed molecules are those with lower double bond equivalents and lower aromaticity. 2D-COS (two-dimensional correlation spectroscopy) demonstrated that the flocs generated by Al13 and AlCl3 had the same organic release patterns but different intensities, while the flocs generated in the micro-SiO2 and nano-SiO2 systems had different organics release patterns. Abundant aluminum hydrolysates with low polymerization and amorphous Al(OH)3 would be produced from AlCl3 during the coagulation process and then undergo hydroxyl‑bridging reaction and crystallization during floc aging, thus releasing more HS with high aromaticity into the supernatant; in comparison, prehydrolyzed Al13 produces a more stable floc and releases less HS during aging. The flocs produced by nano-SiO2 and Al-based coagulants release higher aromaticity HS into the water than those produced by micro-SiO2, which may be related to the formation of more highly polymerized degree hydrolysates and nanocrystalline Al(OH)3 in the nano-SiO2 system. The flocs generated in water with micro-SiO2 may contain a large amount of Al-OH and have a loose structure, thus further absorbing NOM, such as protein-like substances and LWM-N. In contrast, the flocs generated from nano-SiO2 possess abundant adsorbed water and a denser structure; thus, organic matter cannot be absorbed stably.
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Affiliation(s)
- Junjie Yu
- State Key Laboratory of Environmental Aquatic Chemistry, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; Yangtze River Delta Branch, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Yiwu City, Zhejiang Province 322000, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Hui Xu
- State Key Laboratory of Environmental Aquatic Chemistry, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; Yangtze River Delta Branch, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Yiwu City, Zhejiang Province 322000, China
| | - Dongsheng Wang
- College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058, China
| | - Hongyan Sun
- School of Environmental and Chemical Engineering, Foshan University, Foshan 528000, China
| | - Ruyuan Jiao
- State Key Laboratory of Environmental Aquatic Chemistry, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; Yangtze River Delta Branch, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Yiwu City, Zhejiang Province 322000, China
| | - Yang Liu
- State Key Laboratory of Environmental Aquatic Chemistry, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Zhiyuan Jin
- State Key Laboratory of Environmental Aquatic Chemistry, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Shuo Zhang
- State Key Laboratory of Environmental Aquatic Chemistry, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; University of Chinese Academy of Sciences, Beijing 100049, China
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7
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Effect of modified microbial flocculant on membrane fouling alleviation in a hybrid aerobic granular sludge membrane system for wastewater reuse. Sep Purif Technol 2022. [DOI: 10.1016/j.seppur.2022.120819] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
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8
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Zhang D, Zhang K, Chen K, Xue Y, Liang J, Cai Y. Mitigation of organic fouling of ultrafiltration membrane by high-temperature crayfish shell biochar: Performance and mechanisms. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 820:153183. [PMID: 35051453 DOI: 10.1016/j.scitotenv.2022.153183] [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: 11/30/2021] [Revised: 12/24/2021] [Accepted: 01/12/2022] [Indexed: 05/09/2023]
Abstract
The paper applied crayfish shell (CFS) biochar to the mitigation of ultrafiltration (UF) membrane fouling induced by humic acid (HA) and sodium alginate (SA). Results indicated that the high adsorption capacity of CFS800 to HA made it effective in alleviating the irreversible membrane fouling induced by HA, and the cross-linking reaction between the hydroxyl calcium components on CFS800 and SA reduced the reversible membrane fouling induced by SA rapidly. Further analysis showed that the "hydrogel flocs" generated by the cross-linking reaction would accumulate on the surface of the substrate membrane and form an amorphous hydrogel layer to intercept the subsequent foulant and purify the water quality further. Meanwhile, the mitigation performance of CFS800 was twice more than that of commercial powder activated carbon (PAC), and the dosage was the main factor affecting its practical application performance and thus could be considered as a promising material in alleviating membrane fouling induced by HA and SA. More importantly, the findings of the present study gave a new sight towards the application of biochar.
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Affiliation(s)
- Dawei Zhang
- School of Civil Engineering, Wuhan University, Wuhan, Hubei 430072, PR China
| | - Kejing Zhang
- School of Civil Engineering, Wuhan University, Wuhan, Hubei 430072, PR China
| | - Keyan Chen
- School of Civil Engineering, Wuhan University, Wuhan, Hubei 430072, PR China
| | - Yingwen Xue
- School of Civil Engineering, Wuhan University, Wuhan, Hubei 430072, PR China.
| | - Jiatong Liang
- School of Civil Engineering, Wuhan University, Wuhan, Hubei 430072, PR China
| | - Yu Cai
- School of Civil Engineering, Wuhan University, Wuhan, Hubei 430072, PR China
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9
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Zhang B, Mao X, Tang X, Tang H, Zhang B, Shen Y, Shi W. Pre-coagulation for membrane fouling mitigation in an aerobic granular sludge membrane bioreactor: A comparative study of modified microbial and organic flocculants. J Memb Sci 2022. [DOI: 10.1016/j.memsci.2021.120129] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
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10
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Wang G, Wang J, Yu T, Guo X, Chen Y. Efficient removal of humic acid in water using a novel TiO 2 composite with biochar doping. RSC Adv 2022; 12:31966-31975. [PMCID: PMC9641702 DOI: 10.1039/d2ra05358f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2022] [Accepted: 10/10/2022] [Indexed: 11/11/2022] Open
Abstract
Titanium dioxide modified with biochar (Ti–C) was prepared by a sol–gel method for the degradation of humic acid (HA) in aqueous solutions.
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Affiliation(s)
- Guoqiao Wang
- College of Architecture and Environment, Sichuan University, Chengdu 610065, China
- Shenyang Municipal Bureau of Public Utilities, Shengyang, 110011, China
| | - Jiawei Wang
- College of Architecture and Environment, Sichuan University, Chengdu 610065, China
| | - Tian Yu
- College of Architecture and Environment, Sichuan University, Chengdu 610065, China
| | - Xin Guo
- Chengdu Academy of Environmental Protection Sciences, Chengdu, 610072, China
| | - Yao Chen
- College of Architecture and Environment, Sichuan University, Chengdu 610065, China
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11
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Yan M, Shen X, Gao B, Guo K, Yue Q. Coagulation-ultrafiltration integrated process for membrane fouling control: Influence of Al species and SUVA values of water. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 793:148517. [PMID: 34174605 DOI: 10.1016/j.scitotenv.2021.148517] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/19/2021] [Revised: 06/13/2021] [Accepted: 06/14/2021] [Indexed: 05/09/2023]
Abstract
Natural organic matter (NOM) pollution is a great challenge for the ultrafiltration (UF) process owing to the inevitable membrane fouling. In this study, three Al species coagulants (Ala/Alb/Alc) and their composites in combination with Poly dimethyl ammonium chloride (PolyDMDAAC) were used as a pretreatment strategy for the UF process. Then, test waters with different NOM fractions (i.e., humic acid, fulvic acid, protein, and polysaccharide) were prepared to analyze the effects of NOM characteristics on membrane fouling behaviors. The results indicated that compared with Alb and Alc, Ala showed higher removal efficiencies for hydrophobic NOM, aromatic organic matters, and suspended particles, but a limited effect on removing dissolved organic carbon (DOC). Ala or Ala-PolyDMDAAC effectively mitigated membrane fouling by removing the hydrophobic NOM in the coagulation process and forming the porous cake layer in the UF process. The test waters with higher specific ultraviolet absorbance (SUVA) resulted in more severe total and reversible membrane fouling but lighter irreversible fouling. After pretreatment by Ala or Ala-PolyDMDAAC, water samples with the medium SUVA value exhibited remarkable alleviation of membrane fouling due to the formation of large, compact, and robust flocs, as well as the construction of loose and poriferous cake layer on the membrane surface. Although hydrophilic NOM was challenging to be removed by coagulation, the interception and re-adsorption of porous cake layers contributed to the alleviation of irreversible fouling.
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Affiliation(s)
- Mengjiao Yan
- Key Laboratory of Water Pollution Control and Resource Reuse, School of Environmental Science and Engineering, Shandong University, Qingdao 266000, Shandong, PR China
| | - Xue Shen
- Resources and Environment Innovation institute, Shandong Jianzhu University, Jinan 250101, China
| | - Baoyu Gao
- Key Laboratory of Water Pollution Control and Resource Reuse, School of Environmental Science and Engineering, Shandong University, Qingdao 266000, Shandong, PR China.
| | - Kangying Guo
- Key Laboratory of Water Pollution Control and Resource Reuse, School of Environmental Science and Engineering, Shandong University, Qingdao 266000, Shandong, PR China.
| | - Qinyan Yue
- Key Laboratory of Water Pollution Control and Resource Reuse, School of Environmental Science and Engineering, Shandong University, Qingdao 266000, Shandong, PR China
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12
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Ma B, Wang B, Hu C. Dynamic regulation of Al-based floc cake layers by spiral rotation during ultrafiltration in drinking water treatment. ENVIRONMENTAL RESEARCH 2021; 196:110353. [PMID: 33130167 DOI: 10.1016/j.envres.2020.110353] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/08/2020] [Revised: 09/27/2020] [Accepted: 10/16/2020] [Indexed: 06/11/2023]
Abstract
Integrated ultrafiltration (UF) membrane-based processes are promising drinking water treatment technologies. However, the membrane module always remains static, resulting in membrane fouling through the gradual formation of a thick cake layer. As floc-based cake layers are loose, in the present study, a membrane module spiral rotation was introduced with the aim of regulating the cake layers. The cake layer thickness readily decreased and the UF membrane fouling was alleviated. The results showed that Al-based flocs were not easily removed from the membrane surface during rotation due to its low density; as a result, the likelihood of humic acid (HA) reaching the membrane surface was low. Computational fluid dynamics indicated that a strong shearing force was generated with high rotation height. Thus, the cake layer thickness was easily regulated, and the UF membrane fouling was further alleviated. However, the floc-based cake layer could be broken by strong shearing forces, thereby allowing HA molecules to directly reach the membrane surface and further aggravating membrane fouling. In comparison to alkaline condition, the UF membrane performed better under acidic conditions, particularly in terms of HA removal, due to the smaller floc size and higher positive charge. Additionally, excellent UF membrane performance was also observed when treating raw water, indicating the potential application.
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Affiliation(s)
- Baiwen Ma
- Key Laboratory of Drinking Water Science and Technology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, China; University of Chinese Academy of Sciences, Beijing, 100049, China; Jiangsu Collaborative Innovation Center of Technology and Material of Water Treatment, Suzhou, 215009, China
| | - Bodong Wang
- Key Laboratory of Drinking Water Science and Technology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, China; School of Environmental and Municipal Engineering, Xi'an University of Architecture and Technology, Xi'an, 710055, China
| | - Chengzhi Hu
- Key Laboratory of Drinking Water Science and Technology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, China; University of Chinese Academy of Sciences, Beijing, 100049, China; Jiangsu Collaborative Innovation Center of Technology and Material of Water Treatment, Suzhou, 215009, China.
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13
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Ding Y, Li T, Qiu K, Ma B, Wu R. Membrane fouling performance of Fe-based coagulation-ultrafiltration process: Effect of sedimentation time. ENVIRONMENTAL RESEARCH 2021; 195:110756. [PMID: 33493536 DOI: 10.1016/j.envres.2021.110756] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/05/2020] [Revised: 01/12/2021] [Accepted: 01/13/2021] [Indexed: 05/09/2023]
Abstract
Pre-coagulation is commonly used with ultrafiltration (UF) to alleviate the membrane fouling. Compared to conventional coagulation-sedimentation-UF (CSUF) processes, the direct coagulation-UF (CUF) processes are widely believed to perform better due to the formation of a looser cake layer. It is however shown in this study that not only the density of a cake layer, but also its thickness as well, can affect the membrane fouling behavior, which therefore are influenced by both the sedimentation time and flocs characteristics. Herein, the membrane fouling performance of Fe-based coagulation-UF process was systematically investigated with different sedimentation times. A critical threshold of 30 min was observed at the lab-scale: if shorter than that, the membrane fouling depended mainly on the cake layer density, and thus CUF outperformed CSUF; but when the sedimentation time was over 30 min, the cake layer thickness turned to be the dominant factor, thereby resulting in CSUF performing better. Furthermore, it was shown that the critical sedimentation time was decided by flocs characteristics. A lower water temperature induced the formation of irregular flocs with a lower fractal dimension, and the corresponding cake layer exhibited an almost identical density with increasing sedimentation time. In this regard, CSUF processes were constantly superior to CUF as the cake layer thickness decreased. On the other hand, a critical sedimentation time reappeared because of the higher floc fractal dimension under acidic conditions. This work showed for the first time that the membrane fouling of CSUF was up to the sedimentation time, and it was possible to outperform CUF if the sedimentation time exceeded a critical threshold. Such a finding is crucial to the future development of coagulation integrated UF processes.
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Affiliation(s)
- Yanyan Ding
- State Key Laboratory of Pollution Control and Resource Reuse, School of Environmental Science and Engineering, Tongji University, Shanghai, 200092, China; Key Laboratory of Drinking Water Science and Technology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, China; University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Tong Li
- Institute of Environmental Research at Greater Bay Area; Key Laboratory for Water Quality and Conservation of the Pearl River Delta, Ministry of Education, Guangzhou University, Guangzhou, 510006, China
| | - Kaipei Qiu
- School of Resources and Environmental Engineering, East China University of Science and Technology, Shanghai, 200237, China
| | - Baiwen Ma
- Key Laboratory of Drinking Water Science and Technology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, China.
| | - Ruijun Wu
- State Key Laboratory of Membrane Materials and Membrane Applications, Tianjin Motimo Membrane Technology Co., Ltd., Tianjin, 300457, China
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14
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Park JW, Lee SJ, Hwang DY, Seo S. Removal of microplastics via tannic acid-mediated coagulation and in vitro impact assessment. RSC Adv 2021; 11:3556-3566. [PMID: 35424293 PMCID: PMC8694221 DOI: 10.1039/d0ra09645h] [Citation(s) in RCA: 32] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2020] [Accepted: 01/12/2021] [Indexed: 11/23/2022] Open
Abstract
Microplastics are distributed in oceans worldwide, and the negative effects of microplastics on the environment and human health are increasing. Generally, three methods are employed to remove microplastics: filtration, biological degradation, and coagulation. Of these methods, filtration is the most commonly used but depends on the filter size or degree of microplastic coagulation. Although Fe- or Al-salts are generally used for coagulation via electrostatic interactions between metal ion and microplastics, their microplastic removal efficiency is less than 40%, and the smaller the size of microplastics, the lower is the removal efficiency. In order to improve the removal efficiency, metal-phenolic coordinate bonds were newly utilized for microplastic coagulation. Plant-derived tannic acid contributed to interfacial bridging between the microplastics and Fe3+. Using 0.5 μm polystyrene beads as model microplastics, a removal efficiency of more than 90% within 5 min was achieved. Since microplastics mostly accumulate in the gut of animals, rat intestine IEC18 cells exposed to purified water from the microbead suspension were risk assessed, revealing that water purified using the coagulation-based method reduced oxidative stress and inflammatory cytokines to levels similar to those in cells exposed to water without microbeads.
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Affiliation(s)
- Jun Woo Park
- Department of Biomaterials Science (BK21 FOUR Program), College of Natural Resources and Life Science, Life and Industry Convergence Research Institute, Pusan National University Miryang 50463 Republic of Korea
| | - Su Jin Lee
- Department of Biomaterials Science (BK21 FOUR Program), College of Natural Resources and Life Science, Life and Industry Convergence Research Institute, Pusan National University Miryang 50463 Republic of Korea
| | - Dae Youn Hwang
- Department of Biomaterials Science (BK21 FOUR Program), College of Natural Resources and Life Science, Life and Industry Convergence Research Institute, Pusan National University Miryang 50463 Republic of Korea
| | - Sungbaek Seo
- Department of Biomaterials Science (BK21 FOUR Program), College of Natural Resources and Life Science, Life and Industry Convergence Research Institute, Pusan National University Miryang 50463 Republic of Korea
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15
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Application of sodium alginate as a coagulant aid for mitigating membrane fouling induced by humic acid in dead-end ultrafiltration process. Sep Purif Technol 2020. [DOI: 10.1016/j.seppur.2020.117421] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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16
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Recent Purification Technologies and Human Health Risk Assessment of Microplastics. MATERIALS 2020; 13:ma13225196. [PMID: 33213036 PMCID: PMC7698475 DOI: 10.3390/ma13225196] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/25/2020] [Revised: 11/06/2020] [Accepted: 11/13/2020] [Indexed: 02/06/2023]
Abstract
Microplastic (MP)-based contaminants in the environment are pervasive, but standard technologies used for MP identification have not yet been reported. Human beings take up MPs from the environmental ecosystem through the food chain without any particular purification. MPs can penetrate into capillaries from the bloodstream, resulting in endocrine system disorders or toxicity. In this review, we introduced several technologies, such as filtration using membranes, biological degradation, electrocoagulation, and removal using nanoparticles, used for the purification of MPs or related contaminants. Current studies of identification methods of MPs and evaluation tests of MPs exposure-based harmfulness in vitro and in vivo were summarized.
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17
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Sol D, Laca A, Laca A, Díaz M. Approaching the environmental problem of microplastics: Importance of WWTP treatments. THE SCIENCE OF THE TOTAL ENVIRONMENT 2020; 740:140016. [PMID: 32569912 DOI: 10.1016/j.scitotenv.2020.140016] [Citation(s) in RCA: 78] [Impact Index Per Article: 19.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/10/2020] [Revised: 06/03/2020] [Accepted: 06/04/2020] [Indexed: 06/11/2023]
Abstract
The undeniable presence of microplastics (MPs) in soil, air and, especially, in the aquatic environment has revealed them to be an emerging pollutant. One of the main sources contributing to the release of these microplastics into the environment is wastewater treatment plants (WWTPs). During the treatment of wastewater, these microparticles undergo incomplete retention, which leads to their discharge in huge amounts into water masses. The microplastics removed from the wastewater during the treatment processes usually become entrained in the sewage sludge, which is commonly employed as organic fertilizer. Alarming data regarding the occurrence of MPs in nature and the increasing public awareness of environmental concerns have led to the appearance of numerous studies on this topic in recent years. So, this work is focused on providing an overview of available processes for the removal of microplastics from water and also from sediments. Social demand for the correct and effective management of microplastics is constantly increasing and should be given careful consideration before future action is taken. Recycling is a good option, and policies might be developed in this direction, moving towards a circular and sustainable economy for plastics.
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Affiliation(s)
- Daniel Sol
- Department of Chemical and Environmental Engineering, University of Oviedo, C/Julián Clavería s/n, 33006 Oviedo, Spain
| | - Amanda Laca
- Department of Chemical and Environmental Engineering, University of Oviedo, C/Julián Clavería s/n, 33006 Oviedo, Spain
| | - Adriana Laca
- Department of Chemical and Environmental Engineering, University of Oviedo, C/Julián Clavería s/n, 33006 Oviedo, Spain
| | - Mario Díaz
- Department of Chemical and Environmental Engineering, University of Oviedo, C/Julián Clavería s/n, 33006 Oviedo, Spain.
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18
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Wu S, Hua X, Miao R, Ma B, Hu C, Liu H, Qu J. Influence of floc charge and related distribution mechanisms of humic substances on ultrafiltration membrane behavior. J Memb Sci 2020. [DOI: 10.1016/j.memsci.2020.118260] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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19
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Algae-Laden Fouling Control by Gravity-Driven Membrane Ultrafiltration with Aluminum Sulfate-Chitosan: The Property of Floc and Cake Layer. WATER 2020. [DOI: 10.3390/w12071990] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Gravity-driven membrane (GDM) ultrafiltration is a promising water treatment method due to its low energy consumption and low maintenance. However, the low stable permeability in algae-laden water treatment is currently limiting its wider application. With the ultimate goal of increasing permeability, the aim of this study was to evaluate the effect of a composite coagulant of aluminum sulfate-chitosan (AS-CS) on the GDM filtration performance. In parallel tests with a single AS coagulant and without pre-coagulation, the analysis of membrane fouling resistance and the membrane fouling mechanism were evaluated. The results indicated that the AS-CS/GDM system can alleviate 23.74% and 58.80% membrane fouling, respectively, compared with AS/GDM and the GDM system. The AS-CS/GDM system can effectively remove humic-like substances having a molecular weight (MW) of 3–100 kDa, resulting in removal of 98.32% of algae cells and removal of 66.25% of dissolved organic carbon; the AS-CS/GDM system thereby improved the concentration of attached biomass on the membrane surface with the stronger biodegradability of organic matters. The application of AS-CS pre-coagulation in the GDM process could enhance the proliferation of microorganisms and the removal of low molecular weight humic-like substances. Therefore, the AS-CS/GDM system is a potentially important approach for algae-laden water treatment.
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20
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Wang P, Wang F, Jiang H, Zhang Y, Zhao M, Xiong R, Ma J. Strong improvement of nanofiltration performance on micropollutant removal and reduction of membrane fouling by hydrolyzed-aluminum nanoparticles. WATER RESEARCH 2020; 175:115649. [PMID: 32200335 DOI: 10.1016/j.watres.2020.115649] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/10/2019] [Revised: 02/13/2020] [Accepted: 02/23/2020] [Indexed: 06/10/2023]
Abstract
Increasing attention has been focused on the removal of micropollutants from contaminated drinking source water. However, low rejection efficiency and membrane fouling still inhibit further application of nanofiltration membrane in this field. Interesting results were found that the residual hydrolyzed-aluminum nanoparticles from supernatant after coagulation and sedimentation strongly improved the nanofiltration performance for micropollutant removal. A simulated raw water containing humic acids, micropollutants and kaolinite clay was employed to investigate the factors of water matrix affecting the nanoparticle-enhanced nanofiltration for micropollutant removal. Results of experiments showed that these hydrolyzed-aluminum nanoparticles easily induced the aggregation of bisphenol-A (BPA) and humic acids in the supernatant. The enhancement of BPA removal was mainly attributed to the repelling interaction between the Al-BPA-DOC complexity and in situ-modified membrane surface during nanofiltration. 'This in situ surface modification by the hydrolyzed-aluminum nanoparticles improved membrane hydrophilicity, roughness and positively-charging capacity. For the treatment of River Songhua water spiked with micropollutant, the percentage removal of BPA was improved to be 88.5%, much more than the case of single nanofiltration without coagulation (60.7%). Meanwhile, the membrane fouling was reduced by 2.13 times than the case of single nanofiltration without the dynamically deposited-layer of nanoparticles. This in situ modification of nanofiltration membrane by hydrolyzed-aluminum nanoparticles achieved excellent removal efficiency for micropollutants from River Songhua water background.
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Affiliation(s)
- Panpan Wang
- State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin, 150090, China
| | - Feihong Wang
- State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin, 150090, China
| | - Haicheng Jiang
- State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin, 150090, China
| | - Yuchao Zhang
- State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin, 150090, China
| | - Ming Zhao
- State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin, 150090, China
| | - Ruohan Xiong
- State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin, 150090, China
| | - Jun Ma
- State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin, 150090, China.
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21
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Tang J, Jia H, Mu S, Gao F, Qin Q, Wang J. Characterizing synergistic effect of coagulant aid and membrane fouling during coagulation-ultrafiltration via in-situ Raman spectroscopy and electrochemical impedance spectroscopy. WATER RESEARCH 2020; 172:115477. [PMID: 31945650 DOI: 10.1016/j.watres.2020.115477] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/23/2019] [Revised: 01/03/2020] [Accepted: 01/05/2020] [Indexed: 06/10/2023]
Abstract
The polymer coagulant aid can effectively enhance the coagulation-ultrafiltration (C-UF) process for the purification of drinking water. However, when coagulant aid entered the filtration, it may also cause serious membrane fouling as polymer. In-situ Raman spectroscopy and electrochemical impedance spectroscopy(EIS) were applied to monitor the effects of coagulant aids on the membrane. The causes of fouling were assisted discussed through stage cleaning of the membrane. The equivalent circuit fitting was performed on the EIS data and the Raman spectral data were statistically analyzed after peak fitting. EIS and the cluster analysis of Raman spectroscopy provided an earlier feedback on membrane fouling layers compared to flux. The cause of membrane fouling was explained via variation of characteristic functional groups obtained by Raman spectroscopy. When the molecular weight of the coagulant aid was 160 times,80 times and 16 times larger than the MWCO of the UF membrane, the equivalent circuit obtained by fitting the EIS of the UF system satisfied Rs + c(QpRp), Rs(QcRc)(QpRp) and Rs(Qt(Rc(QpRp))) respectively. Partial correlation analysis showed that the corresponding factors causing irreversible fouling of membrane were humic acid(HA), HA and coagulant aids, coagulant aids. Combined with the mean roughness (Ra) of membrane, the coagulant aid performed differently in the cleaning of contaminated membrane and also affected the cleaning of HA.
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Affiliation(s)
- Juan Tang
- State Key Laboratory of Membrane filtration and Processes, Tianjin Polytechnic University, Tianjin, 300387, China; School of Environmental Science and Engineering, Tianjin Polytechnic University, Tianjin, 300387, China
| | - Hui Jia
- State Key Laboratory of Membrane filtration and Processes, Tianjin Polytechnic University, Tianjin, 300387, China; School of Environmental Science and Engineering, Tianjin Polytechnic University, Tianjin, 300387, China
| | - Situ Mu
- School of Environmental Science and Engineering, Tianjin University, Tianjin, 300350, China
| | - Fei Gao
- State Key Laboratory of Membrane filtration and Processes, Tianjin Polytechnic University, Tianjin, 300387, China; School of Environmental Science and Engineering, Tianjin Polytechnic University, Tianjin, 300387, China
| | - Qingwen Qin
- State Key Laboratory of Membrane filtration and Processes, Tianjin Polytechnic University, Tianjin, 300387, China; School of Environmental Science and Engineering, Tianjin Polytechnic University, Tianjin, 300387, China
| | - Jie Wang
- State Key Laboratory of Membrane filtration and Processes, Tianjin Polytechnic University, Tianjin, 300387, China; School of Environmental Science and Engineering, Tianjin Polytechnic University, Tianjin, 300387, China.
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22
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Long Y, You X, Chen Y, Hong H, Liao BQ, Lin H. Filtration behaviors and fouling mechanisms of ultrafiltration process with polyacrylamide flocculation for water treatment. THE SCIENCE OF THE TOTAL ENVIRONMENT 2020; 703:135540. [PMID: 31761369 DOI: 10.1016/j.scitotenv.2019.135540] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/03/2019] [Revised: 11/05/2019] [Accepted: 11/13/2019] [Indexed: 05/09/2023]
Abstract
This study aims to investigate thermodynamic mechanisms of filtration behaviors of ultrafiltration (UF) process with polyacrylamide (PAM) flocculation for surface water treatment, which has not been investigated previously. It was interestingly found that, filtration of durably mixed sodium alginate (SA) solution corresponded to an extraordinarily high specific filtration resistance (SFR) (3.28 × 1014 m·kg-1 without polyacrylamide addition) and a V-shaped profile of SFR characterized by a sharp fall followed by a correspondingly sharp rise along with the increase in PAM addition concentration. Experimental characterizations suggested that, membrane fouling was mainly caused by the gel layer formation rather than the pore clogging and cake/floc formation. Rather than the chemical composition change, the changes of the solution physicochemical properties (pH and zeta potential) and foulant morphology are associated with above-mentioned interesting filtration behaviors. Accordingly, the thermodynamic mechanisms of the filtration behaviors were proposed. It was proposed that, the thermodynamics of polymeric network described by the Flory-Huggins lattice theory were responsible for the extraordinarily high SFR of SA gel layer. Low dosage of PAM addition decreased the negative zeta potential and homogeneity of the gel system, causing the reduced SFR. In contrast, further PAM addition increased the negative zeta potential and homogeneity of the gel system, and then increased the SFR of the gel layer. These results reasonably explained the V-shaped profile of SFR. This study provided significant insights into the effects of PAM addition on ultrafiltration behaviors of alginate solution.
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Affiliation(s)
- Ying Long
- College of Geography and Environmental Sciences, Zhejiang Normal University, Jinhua 321004, China
| | - Xiujia You
- College of Geography and Environmental Sciences, Zhejiang Normal University, Jinhua 321004, China
| | - Yifeng Chen
- College of Geography and Environmental Sciences, Zhejiang Normal University, Jinhua 321004, China
| | - Huachang Hong
- College of Geography and Environmental Sciences, Zhejiang Normal University, Jinhua 321004, China
| | - Bao-Qiang Liao
- Department of Chemical Engineering, Lakehead University, 955 Oliver Road, Thunder Bay, Ontario P7B 5E1, Canada
| | - Hongjun Lin
- College of Geography and Environmental Sciences, Zhejiang Normal University, Jinhua 321004, China.
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23
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Chen W, Mo J, Du X, Zhang Z, Zhang W. Biomimetic dynamic membrane for aquatic dye removal. WATER RESEARCH 2019; 151:243-251. [PMID: 30599283 DOI: 10.1016/j.watres.2018.11.078] [Citation(s) in RCA: 152] [Impact Index Per Article: 30.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/27/2018] [Revised: 11/24/2018] [Accepted: 11/28/2018] [Indexed: 05/25/2023]
Abstract
This study utilized physical adsorption and filtration of carbon nanotubes (CNTs) and laccases to fabricate biomimetic dynamic membrane (BDM) for the advanced treatment of dye wastewater. In BDM, the adsorption, enzymatic degradation and membrane separation demonstrated a synergism effect on pollutant removal. At first, the fabrication methods of BDM were investigated, and the mixed filtration for laccases and CNTs showed a better performance than the stepwise filtration. Furthermore, the operation parameters of BDM, including CNTs and laccase loading amounts, dye concentration, agitation speed and transmembrane pressure (TMP), were studied. Suitable CNTs and laccase amounts could reduce filtration resistance and increase catalysis efficiency, while moderate TMP and agitation speed were in favor of boosting the BDM structure for catalysis and permeability. Optimized operation parameters (CNT loading amount = 20 g m-2, laccase loading amount = 74.6 g m-2, agitation speed = 100 rpm, and TMP = 1.0 bar) sustained a high removal rate, and the flux was over 120 L m-2 h-1, even for 7 operation cycle' tests. BDM exhibited an excellent dye removal rate, stable flux and great antifouling capacity, on the ground that adsorption saturation and foulant may be alleviated "online and in-situ" by the enzymatic degradation. Afterwards, the bionic layer on BDM, after absorption saturation and catalyst deactivation, could be eliminated rapidly by carrying out a simple backwash cleaning operation, then a new one could be fabricated immediately. Therefore, BDM is a good candidate for functional membrane materials in future water treatment.
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Affiliation(s)
- Wensong Chen
- School of Environmental Science and Engineering, Guangzhou, 510006, China
| | - Jiahao Mo
- School of Environmental Science and Engineering, Guangzhou, 510006, China
| | - Xing Du
- School of Civil and Transportation Engineering, Guangdong University of Technology, Guangzhou, 510006, China
| | - Zhien Zhang
- William G. Lowrie Department of Chemical and Biomolecular Engineering, The Ohio State University, Columbus, OH, 43210, USA
| | - Wenxiang Zhang
- School of Environmental Science and Engineering, Guangzhou, 510006, China.
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24
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Bai L, Liu Y, Ding A, Ren N, Li G, Liang H. Surface coating of UF membranes to improve antifouling properties: A comparison study between cellulose nanocrystals (CNCs) and cellulose nanofibrils (CNFs). CHEMOSPHERE 2019; 217:76-84. [PMID: 30414545 DOI: 10.1016/j.chemosphere.2018.10.219] [Citation(s) in RCA: 53] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/06/2018] [Revised: 10/28/2018] [Accepted: 10/30/2018] [Indexed: 05/27/2023]
Abstract
The inherent properties of hydrophilicity and environmental preferability of cellulose nanocrystals (CNCs) and cellulose nanofibers (CNFs) make them great candidates for application in water-treatment membranes. In this study, the antifouling properties of CNCs and CNFs, modified ultrafiltration (UF) membranes, were directly compared. A facile modification method was conducted by coating CNCs and CNFs on the surface of polyethersulfone (PES) membranes to prepare CNC-coating membranes and the CNF-coating membranes. Membrane surface morphology was characterized by atomic force microscopy (AFM), and the results showed that the CNF-coating membranes exhibited greater surface roughness than the CNC-coating membranes. Pure water flux measurements demonstrated that the flux of the CNC-coating membranes was slightly lower than that of the CNF-coating membranes. Antifouling properties were evaluated and compared for the two types of membranes by filtration of NOM foulant models, humic acid (HA) and bovine serum albumin (BSA). The results showed that the antifouling properties of the modified membranes were enhanced through the coating of either CNCs or CNFs to a control PES membrane. The CNC-coating membranes outperformed the CNF-coating membranes in alleviating both reversible fouling and irreversible fouling caused by HA and BSA. In addition, the antifouling performance of the coating membranes was enhanced with increased coating content.
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Affiliation(s)
- Langming Bai
- State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, Harbin, 150090, China
| | - Yatao Liu
- State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, Harbin, 150090, China
| | - An Ding
- State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, Harbin, 150090, China
| | - Nanqi Ren
- State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, Harbin, 150090, China
| | - Guibai Li
- State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, Harbin, 150090, China
| | - Heng Liang
- State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, Harbin, 150090, China.
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