JOURNAL OF MEMBRANE SCIENCE
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2018
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IF 6.578
Wenyu Wang,Qinyan Yue,Kangying Guo,Fan Bu,Xue Shen,Baoyu Gao
The membrane fouling is a challenge for the application of ultrafiltration , one of which the cake layer is the main influencing factor. However, the pros and cons of cake layer generated in the coagulation-ultrafiltration (C-UF) process needs to be explored. This study was carried out to investigate that the effect of a cake layer on the membrane fouling behavior with three Al species coagulants for different effluents. The results indicated that the fouling mechanisms of cake layer under different effluents conditions were diverse due to the particle characteristics. The Al hydrolysis that accompanied by the interaction between Al species coagulants and the –OH/-COOH functional groups of humic acid were conducted, and the effluents of Al a presented lighter membrane fouling. Meanwhile, the components mainly trapped by the membrane were soluble microbial products, protein, polypeptides and amino acid-like materials during C-UF process, because of the decrease in the proportion of fluorescence response. For the less/compact cake layer (system 2), the average of the external and internal membrane resistances were about 25 × 10 10 m −1 and 21 × 10 10 m −1 , respectively, which caused severe membrane fouling. It was concluded that the poriferous/loose cake layer could effectively alleviate membrane fouling by re-adsorbing some organic matters.
研究领域:
环境科学
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水处理工程
✓ 已验证
DOI
高影响因子
CHEMOSPHERE
·
2022
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IF 8.943
Xuesong Ye,Zhencheng Ge,Qiliang Xiao,Bohan Liu,Meng Chen,Fangmin Wu,Jun Nan
In remote areas, low-pressure ultrafiltration membrane (LPM) systems can be applied in decentralized water supplies for the treatment of groundwater containing Fe 2+ , Mn 2+ , and NH 4 + . However, improving the performance of the LPM systems, such as the stable flux and removal capacity, presents a challenge. In this study, a novel opposite-flow low-pressure ultrafiltration membrane (O-LPM) system was applied, and its performance was evaluated. Experimental results showed that after 46 days of operation, the steady flux of the O-LPM systems were 1.87-fold and 1.74-fold higher than that of the conventional D-LPM systems under Mn 2+ concentration of 0.3 mg L −1 and 1.5 mg L −1 , respectively. With a mixed pollutant system containing Fe 2+ (0.5 mg L −1 ), Mn 2+ (0.3 mg L −1 ), and NH 4 + (1.0 mg L −1 ), the O-LPM-ripening period for Mn 2+ removal was shortened from 16 days to 8 days, and the NH 4 + removal efficiency was increased from 61.46% to 80.97%. The bio-cake layer in the O-LPM systems was thinner and had a higher uniformity than in the D-LPM systems, resulting in a larger stable flux range. The relative abundance of functional bacteria (MnOB, IOB, and NOB) was generally higher in O-LPM systems than in the D-LPM systems. Overall, these results are of high relevance for groundwater treatment in remote areas, providing guidance for the widespread application of the O-LPM system in decentralized water supplies.
研究领域:
环境工程
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微生物学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2023
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IF 8.6
Jiangshuai Hu,Bin Ji,Rui Wang,Danting Shi,Senlin Shao
A microbe-rich cake layer (i.e., a membrane biofilm) may maintain a stable hydraulic resistance at low fluxes because the microorganisms may decompose organic foulants and create cavities in the cake layer. However, these microorganisms cannot decompose the inorganic particles, which can increase cake resistance because of the synergistic fouling effect with organic foulants. To gain a better understanding of the effect of microorganisms on the microbe-rich cake layer containing inorganic particles, we investigated the change in hydraulic resistance, structure, and composition during the transition of cake layers from a microbe-poor state to a microbe-rich state, at the flux of 5, 10, and 30 L·m −2 ·h −1 . And we used SiO 2 particles (2.5 μm in diameter) and sodium alginate to simulate inorganic particles and organic foulants. The results showed that when the cake layer was transformed from a microbe-poor state to a microbe-rich state, the hydraulic resistance was reduced, the structure became looser, and inorganic particles were partially detached. These changes were more pronounced for the cake layer under an ultra-low flux of 5 L·m −2 ·h −1 , with 62% and 47% reductions in the hydraulic resistance and inorganic particles, respectively. These results indicated that the fouling by inorganic particles could be reduced by the microorganisms at ultra-low fluxes. Cake composition analysis , forces balance analysis, and computational fluid dynamics simulation suggested that the reduced fouling could be derived from the reasons 1) the biodegradation of organic foulants could promote the detachment of inorganic particles, and 2) the microbial-induced cavities at ultra-low fluxes could reduce the synergistic fouling effect by inorganic particles and organic foulants.
研究领域:
环境工程
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微生物学
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膜技术
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF MEMBRANE SCIENCE
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2025
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IF 9
Situ Mu,Ruihang Zheng,Junjun Ma,Chun Liu,Jing Zhang,Jie Wang
Membrane fouling is an important obstacle to the development of membrane technology, and understanding the fouling mechanism and the sequential structure of the cake layer is critical for fouling control. In this study, a solid-phase fluorescence optic fiber (SPFOF) platform was established, combined with parallel factor analysis (PARAFAC) and response surface methodology (RSM), to achieve quantitative monitoring of mixed foulants on the membrane surface. The membrane fouling mechanism and cake layer structure were further investigated. The results indicated that the deposition amount of protein (PN) substances exhibited a linear positive correlation with fluorescence intensity, whereas solid-phase humic acid (HA) demonstrated a fluorescence quenching effect. The intermediate blocking and cake filtration were identified as the dominant membrane fouling mechanisms. The membrane fouling of PN and HA had spatiotemporal dynamic changes during the filtration process. Initially, PN was preferentially adsorbed onto the membrane surface, followed by the rapid deposition of HA facilitated by the subsequent formation of the PN-HA structure. Compared with liquid excitation-emission matrix and chemical concentration methods, the SPFOF method had both accuracy and repeatability, and had significant advantages in the quantitative characterization of foulants at the interface of the membrane.
研究领域:
环境科学
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膜技术
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水处理
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分析化学
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环境工程
✓ 已验证
产品关联
DOI
高影响因子
SCIENCE OF THE TOTAL ENVIRONMENT
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2022
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IF 10.753
Zhenxiang Pan,Bizhen Zeng,Hongjun Lin,Jiaheng Teng,Hanmin Zhang,Huachang Hong,Meijia Zhang
While transparent exopolymer particles (TEP) has high fouling potential, its underlying fouling mechanisms have not yet been well revealed. In current work, fouling characteristics of TEP under different Ca 2+ concentrations (0 to 1.5 mM) were investigated. TEP quantification and filtration tests showed that TEP contents increased with Ca 2+ concentration, while TEP's specific filtration resistance (SFR) under the influence of Ca 2+ concentration presented a unimodal pattern. The peak of TEP's SFR reached at Ca 2+ concentration of 1 mM when SA concentration was 0.3 g·L −1 . A series of characterizations suggested that microstructure transformation of TEP particles was the main contributor to the resistance variations of TEP solution. The optical microscope observation showed that above and below the critical Ca 2+ concentration (1 mM when SA concentration is 0.3 g·L −1 in this study), the formed TEP existed in the form of c-TEP (average particle size is 0.24 μm) and p-TEP (average particle size is 1.05 μm), respectively. Thermodynamic analysis showed that the adhesion ability of c-TEP (−249,989 and − 303,692 kT) was more than 19 times than that of p-TEP (−12,905 kT), which would accelerate foulant layer formation. In addition, below the critical value, the increased SFR with Ca 2+ concentration could be explained by integrating Flory-Huggins lattice theory with the preferential intermolecular coordination. Above the critical value, the decreased SFR can be attributed to the formation of a “large-size crack structure” cake layer from the p-TEP. This study revealed fundamental mechanisms of membrane fouling caused by TEP, greatly deepening understanding of TEP fouling, and facilitating to development of effective fouling control strategies.
研究领域:
环境科学
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水处理
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膜技术
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热力学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2024
·
IF 8.1
Yatao Liu,Zhenbei Wang,Mingyao Xu,Fei Qi,Chen Li,Dezhi Sun,Jun Nan,Wei Li,Xiao Guan,Amir Ikhlaq
Cake layer is considered to play a crucial role in membrane fouling during the coagulation-ultrafiltration process. However, the contribution of the cake layer on membrane fouling and probable natural organic matter (NOM) removal in this process is unclear, leading to a limited understanding of cake layer and potential secondary utilization. Here, ultrafiltration (UF) membrane fouling contribution, NOM removal, and dynamic membrane application of the cake layer were investigated. Results showed reversible fouling was dominated by cake layer, whereas irreversible fouling was determined by both cake layer and residual NOM in coagulation effluent. Compared with direct UF, the cake layer improved approximately by 15 % of HA removal with molecular weight (MW) of 2000–4000 Da. By optimizing membrane material, HA removal and membrane fouling alleviation were synchronously achieved by cake layer deposition-UF. According to mechanisms analysis, HA removal was attributed to the adsorption or interception of HA with larger MW by the cake layer. Zeta potential and fractal dimension of flocs, and contact angle of the cake layer were closely related to HA removal by cake layer, whereas reversible and irreversible fouling were positively correlated with cake layer thickness and floc fractal dimension respectively. Compared with other dynamic membranes, the cake layer had the best economic performance, which provided application potential on NOM removal in micro-polluted surface water.
研究领域:
环境工程
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水处理
·
膜技术
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF MEMBRANE SCIENCE
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2023
·
IF 9.5
Xuesong Ye,Jun Nan,Xinhao Hu,Zhencheng Ge,Fangmin Wu,Bohan Liu,Meng Chen,Li He,Daliang Xu
Low-pressure ultrafiltration membranes (LPM) are a promising technology for the decentralized water supply. However, currently available ultrafiltration membranes cannot easily achieve the simultaneous removal of ferrous iron (Fe 2+ ), manganese (Mn 2+ ), and ammonia (NH 4 + ). In this study, LPM coupled with three pre-loading layers consisting of manganese dioxide (MnO 2 ) powder, powdered activated carbon (PAC), and zeolite powder, labeled M-LPM, C-LPM, and Z-LPM, respectively, in order to improve the effluent quality and shorten the ripening time without reducing the stable flux. The results show that the stable flux of M-LPM and C-LPM increased, while decreased for Z-LPM due to the viscosity of the pre-loading layer material. The ripening time of the three LPM systems was shortened, with M-LPM showing excellent Mn 2+ removal throughout filtration, while Z-LPM exhibited notable adsorption of Mn 2+ and NH 4 + . CLSM analysis revealed that the biological reactions occurred intensely in the upper area of the bio-cake layer. Based on the analysis of key enzyme genes, the microbial pollutant removal pathways were constructed. In addition, the optimal loading curve of the M-LPM pre-loading layer was established. Overall, the enhanced performance highlights the feasibility and potential of applying the LPM strategy in decentralized water supplies.
研究领域:
环境工程
·
水处理
·
膜技术
·
生物过程
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF MEMBRANE SCIENCE
·
2025
·
IF 9
Yang Zhang,Ziyi Meng,Dongqing Yan,Peng Sun,Qianyu Shang,Ying Liu,Jingang Yao,Jun Wang
Piezoelectric membranes have attracted increasing attention due to their potential to offer pressure-responsive and electromechanical coupling functionalities in pressure-driven filtrations. Despite demonstrated antifouling effectiveness against model foulants, their practical performance within realistic and integrated treatment processes remains inadequately explored. Herein, a piezoelectric PVDF/GO ultrafiltration membrane (PEM) was fabricated and integrated into an online coagulation–ultrafiltration (C–UF) system to mitigate cake layer fouling. During pressure-driven filtration processes, the PEM not only exhibited a self-powered capability with oscillatory output signals (e.g., ∼0.4 V at 30 kPa), but also demonstrated a tunable and markedly enhanced response under dynamic pressure gradients (e.g., ∼1.1 V with a pressure gradient of 2 kPa/s). Based on these observations, a dynamic-pressure-control (DPC) strategy was developed for real-time regulation of piezoelectric output, adaptively responding to the stage-wise progression of cake fouling. Compared with the control membrane, the PEM under DPC operation exhibited ∼60 % lower irreversible filtration resistance and nearly threefold greater cake porosity. Moreover, implementing the DPC procedure for just 3 min per cycle enabled the PEM to sustain robust self-cleaning performance and enhanced permeate quality throughout a multi-cycle filtration test, achieving ∼50 % lower filtration resistance compared to physical cleaning method. Mechanistic analysis suggested that, under piezoelectric activation, the altered floc deposition dynamics and polarization-induced reorganization may act synergistically to shape both the structure and composition of the cake matrix, thereby inhibiting cake growth and subsequent compaction. This work provides a practical operational guidance for retrofitting PEM technology into existing C–UF systems, representing a viable strategy for advancing the application of piezoelectric membranes.
研究领域:
膜技术
·
水处理
·
压电材料
·
环境工程
·
分离过程
✓ 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）