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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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Yu H, Huang W, Liu H, Li T, Chi N, Chu H, Dong B. Application of Coagulation-Membrane Rotation to Improve Ultrafiltration Performance in Drinking Water Treatment. MEMBRANES 2021; 11:membranes11080643. [PMID: 34436406 PMCID: PMC8398328 DOI: 10.3390/membranes11080643] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/27/2021] [Revised: 08/14/2021] [Accepted: 08/18/2021] [Indexed: 11/16/2022]
Abstract
The combination of conventional and advanced water treatment is now widely used in drinking water treatment. However, membrane fouling is still the main obstacle to extend its application. In this study, the impact of the combination of coagulation and ultrafiltration (UF) membrane rotation on both fouling control and organic removal of macro (sodium alginate, SA) and micro organic matters (tannic acid, TA) was studied comprehensively to evaluate its applicability in drinking water treatment. The results indicated that membrane rotation could generate shear stress and vortex, thus effectively reducing membrane fouling of both SA and TA solutions, especially for macro SA organics. With additional coagulation, the membrane fouling could be further reduced through the aggregation of mediate and macro organic substances into flocs and elimination by membrane retention. For example, with the membrane rotation speed of 60 r/min, the permeate flux increased by 90% and the organic removal by 35% in SA solution, with 40 mg/L coagulant dosage, with an additional 70% increase of flux and 5% increment of organic removal to 80% obtained. However, too much shear stress could intensify the potential of fiber breakage at the potting, destroying the flocs and resulting in the reduction of permeate flux and deterioration of effluent quality. Finally, the combination of coagulation and membrane rotation would lead to the shaking of the cake layer, which is beneficial for fouling mitigation and prolongation of membrane filtration lifetime. This study provides useful information on applying the combined process of conventional coagulation and the hydrodynamic shear force for drinking water treatment, which can be further explored in the future.
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Affiliation(s)
- Hongjian Yu
- College of Environmental Science and Engineering, Tongji University, Shanghai 200092, China; (H.Y.); (W.H.); (H.L.); (H.C.); (B.D.)
| | - Weipeng Huang
- College of Environmental Science and Engineering, Tongji University, Shanghai 200092, China; (H.Y.); (W.H.); (H.L.); (H.C.); (B.D.)
| | - Huachen Liu
- College of Environmental Science and Engineering, Tongji University, Shanghai 200092, China; (H.Y.); (W.H.); (H.L.); (H.C.); (B.D.)
| | - Tian Li
- College of Environmental Science and Engineering, Tongji University, Shanghai 200092, China; (H.Y.); (W.H.); (H.L.); (H.C.); (B.D.)
- Key Laboratory of Yangtze River Water Environment, Ministry of Education, Tongji University, Shanghai 200092, China
- State Key Laboratory of Pollution Control and Resource Reuse, Tongji University, Shanghai 200092, China
- Correspondence:
| | - Nianping Chi
- School of Municipal and Geomatics Engineering, Hunan City University, Yiyang 413000, China;
| | - Huaqiang Chu
- College of Environmental Science and Engineering, Tongji University, Shanghai 200092, China; (H.Y.); (W.H.); (H.L.); (H.C.); (B.D.)
- Key Laboratory of Yangtze River Water Environment, Ministry of Education, Tongji University, Shanghai 200092, China
- State Key Laboratory of Pollution Control and Resource Reuse, Tongji University, Shanghai 200092, China
| | - Bingzhi Dong
- College of Environmental Science and Engineering, Tongji University, Shanghai 200092, China; (H.Y.); (W.H.); (H.L.); (H.C.); (B.D.)
- Key Laboratory of Yangtze River Water Environment, Ministry of Education, Tongji University, Shanghai 200092, China
- State Key Laboratory of Pollution Control and Resource Reuse, Tongji University, Shanghai 200092, China
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Li K, Su Q, Li S, Wen G, Huang T. Aging of PVDF and PES ultrafiltration membranes by sodium hypochlorite: Effect of solution pH. J Environ Sci (China) 2021; 104:444-455. [PMID: 33985746 DOI: 10.1016/j.jes.2020.12.020] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2020] [Revised: 12/01/2020] [Accepted: 12/16/2020] [Indexed: 06/12/2023]
Abstract
Sodium hypochlorite (NaClO) is a commonly applied cleaning agent for ultrafiltration membranes in water and wastewater treatment. Long-term exposure to NaClO might change the properties and performance of polymeric membranes, and ultimately shorten membrane lifespan. Active species in NaClO solution vary with solution pH, and the aging effects can change depending on the membrane material. In this study, the aging of polyvinylidene fluoride (PVDF) and polyethersulfone (PES) membranes by NaClO at pH 3-11 was investigated by examining variations in chemical composition, surface charge, surface morphology, mechanical strength, permeability, and retention ability. Polyvinyl pyrrolidone (PVP), which was blended in both membranes, was oxidized and dislodged due to NaClO aging at all investigated pH values, but the oxidation products and dislodgement ratio of PVP varied with solution pH. For the PVDF membrane, NaClO aging at pH 3-11 caused a moderate increase in permeability and decreased retention due to the oxidation and release of PVP. The tensile strength decreased only at pH 11 because of the defluorination of PVDF molecules. For the PES membrane, NaClO aging at all investigated pH resulted in chain scission of PES molecules, which was favored at pH 7 and 9, potentially due to the formation of free radicals. Therefore, a decrease in tensile strength and retention ability, as well as an increase in permeability, occurred in the PES membrane for NaClO aging at pH 3-11. Overall, the results can provide a basis for selecting chemical cleaning conditions for PVDF and PES membranes.
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Affiliation(s)
- Kai Li
- Key Laboratory of Northwest Water Resource, Environment and Ecology, MOE, Xi'an University of Architecture and Technology, Xi'an 710055, China; Shaanxi Key Laboratory of Environmental Engineering, Xi'an University of Architecture and Technology, Xi'an 710055, China
| | - Qian Su
- Key Laboratory of Northwest Water Resource, Environment and Ecology, MOE, Xi'an University of Architecture and Technology, Xi'an 710055, China; Shaanxi Key Laboratory of Environmental Engineering, Xi'an University of Architecture and Technology, Xi'an 710055, China
| | - Shu Li
- Key Laboratory of Northwest Water Resource, Environment and Ecology, MOE, Xi'an University of Architecture and Technology, Xi'an 710055, China; Shaanxi Key Laboratory of Environmental Engineering, Xi'an University of Architecture and Technology, Xi'an 710055, China
| | - Gang Wen
- Key Laboratory of Northwest Water Resource, Environment and Ecology, MOE, Xi'an University of Architecture and Technology, Xi'an 710055, China; Shaanxi Key Laboratory of Environmental Engineering, Xi'an University of Architecture and Technology, Xi'an 710055, China
| | - Tinglin Huang
- Key Laboratory of Northwest Water Resource, Environment and Ecology, MOE, Xi'an University of Architecture and Technology, Xi'an 710055, China; Shaanxi Key Laboratory of Environmental Engineering, Xi'an University of Architecture and Technology, Xi'an 710055, China.
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