Water
·
2019
·Vol. 11
·期 1
·90
·
IF 2.524
Fan Bu,Baoyu Gao,Qinyan Yue,Caiyu Liu,Wenyu Wang,Xue Shen
Ultra-filtration technology has been increasingly used in drinking water treatment due to improvements in membrane performance and lowering of costs. However, membrane fouling is the main limitation in the application of ultra-filtration technology. In this study, we investigated the impact of four different pre-treatments: Coagulation, adsorption, coagulation followed by adsorption (C-A), and simultaneous coagulation and adsorption (C+A), on membrane fouling and natural organic matter removal efficiency. The results showed that adsorption process required a large amount of adsorbent and formed a dense cake layer on the membrane surface leading to severe membrane fouling. Compared to adsorption alone, the coagulation and C-A processes decreased the transmembrane pressure by 4.9 kPa. It was due to less accumulation of particles on the membrane surface. As for water quality, the C-A ultra-filtration process achieved the highest removal efficiencies of natural organic matter and disinfection by-product precursors. Therefore, the addition of adsorbent after coagulation is a potentially important approach for alleviating ultra-filtration membrane fouling and enhancing treatment performance.Keywords:water treatment;ultra-filtration;coagulation;adsorption;membrane fouling
研究领域:
环境科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
Journal of Water Process Engineering
·
2024
·
IF 6.3
Yiwen Wang,Shuanglin Gui,Qinliang Jiang,Pei Han,Hong Wang,Jianping Deng,Tao Chen,Jianxin Li
As the rare earth industry develops and energy efficiency improves, high-salinity rare earth smelting wastewater poses a significant environmental concern. This study applied integrated ultrafiltration (UF) - nanofiltration (NF) membrane technology to treat high-salt rare earth smelting wastewater (Ca 2 ⁺: 10.75 g/L, COD: 3.5 g/L, turbidity: 1.36 NTU) for salt removal and recovery. The effects of UF pretreatment were explored, and the operating parameters for NF were optimized, with the performance of various commercial NF membranes being evaluated. Membrane fouling conditions were also investigated to determine appropriate cleaning methods. The experimental results demonstrate that the UF-NF integrated process is effective in actual wastewater treatment. The calcium ion content in the permeate was reduced from 10.75 g/L in the feed solution to 0.96 g/L, achieving a removal rate of 91.1 %, which meets reuse water standards. Trace amounts of organic molecules in the water, such as 2-Ethylhexyl phosphonic acid mono-2-ethylhexyl ester (P507), were also effectively removed. The removal rates for COD and TOC were notably high at 97.7 % and 98.3 %, respectively. Acid washing, alkaline washing, and water washing were employed to clean the membranes, all of which achieved flux recovery rates exceeding 95.0 %. In summary, the integrated UF-NF process demonstrated outstanding performance in salt recovery/separation of different valence salts from rare earth smelting wastewater. Its excellent operational stability and high flux recovery rates highlight its strong industrial applicability. The exceptional treatment efficacy it displays provides a feasible technological pathway for resource recovery and water recycling in practical applications.
研究领域:
环境工程
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
Water Quality Research Journal
·
2024
·
IF 2.4
Yao Tangchun,Chen Yichao,Wu Wenting,Jin Binbin,Xiao Hua,Wang Qing,Wang Ao,Xu Hang
In this study, we utilized direct ultrafiltration (UF) and integrated microflocculation–ultrafiltration (MF–UF) processes to treat raw water from four distinct sources, covering both dry and heavy rainfall periods. We assessed the effectiveness of microflocculation (MF) as a pretreatment to enhance treatment efficiency under complex water conditions, focusing on its role in mitigating membrane fouling. The results demonstrated the superior adaptability of UF membranes when combined with MF pretreatment, particularly in managing high turbidity during heavy rainfall, a challenge for standalone UF processes in meeting regulatory standards. This integrated approach notably improved UV254 removal efficiency from approximately 60–80%. Additionally, excitation–emission matrix spectroscopy revealed that while the MF–UF process is effective in removing dissolved organic matter (DOM), it faces limitations with high DOM concentrations in raw water. Comparative analysis of membrane flux between the two methods showed that MF pretreatment reduces filtration time, enhances flux rates, and significantly decreases membrane fouling. Finally, scanning electron microscopy further provided insights into the structure and morphology of UF membrane surface filter cakes, illustrating how MF pretreatment contributes to the sustained efficiency of membrane flux. The different water quality conditions were studied. The MF–UF process was studied in realistic conditions. Organic matter and hard particulate matter were studied. Elucidating mechanisms to the MF–UF membrane flux efficiency.
研究领域:
环境科学
·
水处理工程
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING SCIENCE
·
2024
·
IF 4.1
Lei Wu,Menghan Liu,Yuting Chen,Ming Li,Tingting Yin,Cong Ma,Wei Fan
UF is widely used as a wastewater treatment and recycling technology. However, membrane fouling is still an important factor affecting the wide application. In this study, APIm with positive amino group was adsorbed to the surface of the carboxylated polyacrylonitrile (PAN) membrane by electrostatic force to reduce the fouling of sodium alginate (SA) caused by Ca 2+ . The results show that 1 v/v% APIm was selected as the optimal dosage, accompanied by the highest water flux of 330.5 L·m -2 h −1 bar −1 and bovine serum albumin (BSA) rejection rate of 91.0 %. When the concentration of Ca 2+ was increased to 10 mM, the Ca 2+ catch amount increased to 48.25 mg/cm 2 . The main anti-fouling mechanism was that APIm captured a certain amount of Ca 2+ in situ, destroyed the complex structure of sodium alginate (SA) and Ca 2+ . Then the fouling layer was easy to be removed by physical cleaning. At the concentration of 10 mM Ca 2+ , the membrane flux recovery rate of 1 v/v% APIm membrane was increased to 80.1 %. This study demonstrates a fouling control strategy for in-situ removal of Ca 2+ bound SA fouling, providing a new approach for the future development of UF membrane.
研究领域:
环境科学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
RSC Advances
·
2015
·Vol. 5
·期 26
·19807-19817
·
IF 3.84
Yun Zheng,Xueli Gao,Xinyan Wang,Zhaokui Li,Yuhong Wang,Congjie Gao
In this study, a laboratory-scale electrodialysis (ED) system with an effective area of 88 cm2 was used to remove copper and cyanide in simulated and real gold mine effluents. The membrane fouling was characterized by FTIR, SEM-EDX, membrane resistance measurements and static contact angle. The effects of applied voltage, initial concentration, and flux rate on the removal rate of copper and cyanide were investigated. The highest copper (99.41%) and cyanide (99.83%) removal rates were achieved under the following conditions: applied voltage of 25 V, initial concentration of C2 (concentration of copper and cyanide were 47 mg L−1 and 242 mg L−1), and a flux rate of 4.17 mL s−1. In addition, the lowest concentration of copper (0.44 mg L−1), cyanide (0.48 mg L−1) and zinc (0.34 mg L−1) in the treated effluent were all below regulatory limits (copper, cyanide <0.5 mg L−1, zinc <2.0 mg L−1). The results showed the presence of CuCN, [Cu(CN)3]2−, Cu(OH)2, and Zn(OH)2 in the precipitate, and the fouling of anion-exchange membranes (AEMs) could be decreased significantly via pH adjustment. This research provides a new insight into the removal of copper and cyanide from gold mine effluent.
研究领域:
环境科学
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化学工程
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF MEMBRANE SCIENCE
·
2024
·
IF 8.4
Ting Chen,Peng Xu,Minghui Qiu,Xianfu Chen,Zhaoxiang Zhong,Yiqun Fan
The challenge of membrane fouling persistently hinders the advancement of membrane technology . The construction of patterned membrane surfaces is anticipated to mitigate the effects of membrane fouling significantly. In this study, ceramic microfiltration membranes with corrugated patterns were fabricated by 3D printing combined with the dip-coating process. To assess the impact of surface patterning on ceramic membrane performance , we initially compared the pore size and pure water flux between straight and corrugated membrane tubes. Both configurations exhibited similar parameters: a support pore size of approximately 1 μm, a membrane layer pore size of about 110 nm, and a pure water permeance of around 950 L m −2 h −1 ·bar −1 . The corrugated ceramic membranes demonstrated superior anti-fouling properties compared to their straight counterparts during the filtration of nanoparticle suspensions, oil-in-water emulsions, and bacterial suspensions . Specifically, under a nanoparticle suspension concentration of 2000 ppm, a transmembrane pressure of 0.2 MPa, and a flow rate of 1.0 m s −1 , the corrugated membrane achieved a stable flux of approximately 1.7 times greater than that of the straight membrane. Furthermore, we explored the effects of surface patterning on fluid dynamics through numerical simulations. The enhanced turbulence dissipation rate in the patterned membrane tubes suggests increased surface turbulence and an improved capacity to remove contaminants. This research offers novel insights into the development of ceramic membranes with enhanced anti-fouling capabilities for water treatment.
研究领域:
材料科学
·
环境工程
✓ 已验证
产品关联
DOI
高影响因子
CHEMOSPHERE
·
2019
·
IF 5.108
Fan Bu,Baoyu Gao,Xue Shen,Wenyu Wang,Qinyan Yue
Ultrafiltration (UF) technology is considered an efficient water treatment method. In recent years, researchers have been committed to enhancing the treatment efficiency of UF and alleviating membrane fouling. An effective method is to achieve this is through the use of coagulation as a pre-treatment to UF; however, during a long term operation, membrane fouling can occur due to the residual organic matters and the generation of microorganisms . In this study, we combine coagulation and ozonation as a pre-treatment of UF and compare four types of pre-treatment: coagulation, ozonation, coagulation followed by ozonation (C–O) and ozonation followed by coagulation (O–C). Results showed that ozonation alone did not perform well. Both combinations of coagulation and ozonation enhanced the organic matter removal efficiency, although membrane fouling was lowest following the C–O pre-treatment as the microbial load was reduced. While a slight increase in the yield of disinfection by-products was observed with the addition of ozonation, the concentration remained below the Chinese standard for tap water quality (100 μg/L).
研究领域:
环境科学
·
水处理工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF HAZARDOUS MATERIALS
·
2015
·
IF 4.529
Lijuan Feng,Shuang Zhao,Shenglei Sun,Wenyu Wang,Baoyu Gao,Qinyan Yue
The influences of solution pH on coagulation/ultrafiltration (C–UF) process were investigated by using three purified Al species of polyaluminium chloride (PACl). A series of online-simulation experiments were developed to assess the coagulation removal efficiencies (turbidity, UV 254 ), floc properties and membrane fouling in this paper. The results showed that change of pH had a significant impact on coagulation efficiencies, floc properties, membrane flux as well as the whole process. Under acidic condition, the hydrolysis action of aluminum salts was restrained which is bad for charge neutralization. While under alkaline region, absorption was the dominant mechanism to combine HA–Kaolin. Meanwhile, HA is apt to soluble by deprotonating under alkaline region which is hard to remove. These common effects made the experiment results complex. HA removal efficiency of Al a and Al b were higher than that of Al c , but the turbidity removal by Al c was slightly higher under the same pH condition. Flocs generated by Al a at pH 6 had advantages such as larger size and the most loosely structure which contributed the most to alleviating membrane fouling. Membrane fouling with Al b and Al c in alkaline range was more serious than that in acidic range.
研究领域:
环境科学
·
水处理工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
WATER RESEARCH
·
2021
·
IF 11.236
Dachao Lin,Langming Bai,Daliang Xu,Han Zhang,Tiecheng Guo,Guibai Li,Heng Liang
The aim of this study was to evaluate the effects of oxidation on humic-acid-enhanced gypsum scaling in different nanofiltration phases, including the short-term membrane flux behaviors and the long-term ones. On the basic of correlation analysis between the changing physicochemical properties of feed solution and membrane fouling, the inner mechanisms were revealed from aspects of bulk crystallization (interaction between humic acid and inorganic ions) and surface crystallization (compositions and morphologies of surface crystallization). Furthermore, the reliability of applicating differential log-transformed absorbance spectroscopy for predicting membrane fouling was also systematically evaluated. There was an upward trend in short-term membrane fouling with increasing dosage of NaClO, while long-term membrane fouling decreased after an initial increase. During short-term filtration, the enhanced combination between inorganic ions and the humic acid with stronger density of carboxyl groups, which was generated more easily under stronger oxidation conditions, favored the earlier appearance of flux decline. During long-term filtration, the size of bulk crystallization depended on the total content of carboxyl groups in feed solution. Both of them increased firstly and then decreased with increasing oxidation. The terminal fouling layer resistance also shared a similar tendency with them, because the deposition of bulk crystallization on membranes and the formation of dense scaling layer were the direct reasons for the long-term membrane fouling. Furthermore, the differential log-transformed absorbance spectroscopy was proven to be an efficient approach to predict short-term membrane fouling, especially in the wavelength range of 260 to 280 nm. This research could not only provide guidance on alleviating oxidation-enhanced membrane fouling in nanofiltration but also propose an efficient way to predict the membrane fouling which was influenced by the interaction between organic matters and inorganic ions.
研究领域:
环境科学
·
化学工程
✓ 已验证
DOI
高影响因子
Nature Water
·
2025
·
IF 24.1
Chen Yuanmiaoliang,Wang Longchao,del Cerro Martina,Wang Li,Zhang Xuan,Elimelech Menachem,Wang Zhangxin
High-salinity organic wastewaters pose a major challenge for conventional wastewater treatment processes. Here we propose dialysis as an innovative solution to overcome this challenge. Dialysis uses an ultrafiltration (UF) membrane that allows the passage of salts while rejecting the organic substances, operating in a bilateral countercurrent flow mode without the application of hydraulic pressure. Using bench-scale experiments and a model for salt and water transport in leaky membranes, we demonstrate that dialysis can effectively desalinate high-salinity organic wastewaters without diluting the wastewater stream. By comparing the salt/organic selectivity of dialysis and UF using the same membrane, we show that dialysis can effectively fractionate salts and organic substances in high-salinity organic wastewaters. Additionally, we find that, unlike UF, dialysis is almost unaffected by membrane fouling, highlighting its excellent fouling resistance. We conclude by proposing potential high-salinity organic wastewater treatment schemes based on dialysis, paving the way for more sustainable and effective management of challenging wastewaters.
研究领域:
环境科学
·
水处理技术
·
膜分离技术
✓ 已验证
产品关联
DOI
高影响因子
SCIENCE OF THE TOTAL ENVIRONMENT
·
2024
·
IF 8.2
Shengnan Chen,Zhiwei Zhao,Li Li,Fuyi Cui
Ultrafiltration (UF) is widely used in drinking water plants, nevertheless, it still encounters challenges stemming from inevitable membrane fouling caused by natural organic matter (NOM). Herein, this work applied VUV/PS as UF membrane pretreatment and used UV/PS for comparison. VUV/PS system exhibited superior ability in removing NOM compared to UV/PS system. HO and SO 4 − played crucial roles in the degradation. [SO 4 − ]ss was notably higher than [HO ]ss in the systems, yet HO was of greater significance. [HO ]ss and [SO 4 − ]ss in the VUV/PS process were remarkably higher than those in the UV/PS process, due to the function of 185 nm photons. VUV/PS pretreatment basically recovered flux and effectively reduced fouling resistance, with better performance than UV/PS. Fouling mechanism was dominated by multiple mechanisms after UV/PS pretreatment, whereas it was transformed into pore blockage after VUV/PS pretreatment. Moreover, the UF effluent quality after VUV/PS pretreatment outperformed that of UV/PS but fell short of that without pretreatment, possibly due to the generation of abundant low MW substances under the action of HO and SO 4 − . After chlorine disinfection, UV/PS and VUV/PS pretreatments increased the DBPs production and cytotoxicity. Specifically, oxidant PS affected the membrane surface morphology and fouling behaviors, and had no obvious effect on interception performance and mechanical properties. In actual water treatment, VUV/PS and UV/PS pretreatments exhibited excellent performance in alleviating membrane fouling, improving water quality, and reducing DBPs formation and acute toxicity.
研究领域:
环境科学
·
水处理工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2024
·
IF 8.1
Yongbao Chu,Jingyi Zhang,Xuan Hou,Yunxin Zhang,Jiajun Lu,Yan Wang
Membrane fouling is one of the issues that hinder the widespread application of electrified membranes. This study focuses on mitigating membrane fouling caused by natural organic matter (NOM) through pre-coagulation techniques. The effectiveness of pre-coagulation was evaluated based on the flux and removal efficiency of electrified membranes. Pre-coagulation can remove a portion of NOM and reduce the negative surface charge of residual NOM, thereby reducing the attachment of NOM to the surface of electrified membranes. As a result, pre-coagulation effectively increased the flux of electrified membranes for treating water samples containing NOM. Additionally, pre-coagulation alleviated the decrease in surface current density of electrified membranes caused by NOM pollution, leading to improved bisphenol A (BPA) removal performance. The effectiveness of pre-coagulation in enhancing membrane performance depends on the choice of coagulant. Compared to polyferric chloride (PFC), PFC-cationic polyacrylamide composite coagulants (PFC-CPAM) facilitated the aggregation of NOM into larger flocs with a branched structure, demonstrating a stronger capability to mitigate membrane fouling. However, it should be noted that the presence of CPAM may result in irreversible internal fouling due to the polarization effect induced by the electric field. Moreover, when the weight ratio of PFC to CPAM was 1:1, the flocs became overly dense, resulting in reduced flux. This study provides valuable insights for the application of pre-coagulation techniques in mitigating fouling issues in electrified membranes.
研究领域:
环境科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）