Frontiers of Environmental Science & Engineering
·
2022
·Vol. 16
·期 8
·1-16
·
IF 6.048
Liu Xiaoman,Tian Chang,Zhao Yanxia,Xu Weiying,Dong Dehua,Shih Kaimin,Yan Tao,Song Wen
Application of ceramic membrane (CM) with outstanding characteristics, such as high flux and chemical-resistance, is inevitably restricted by membrane fouling. Coagulation was an economical and effective technology for membrane fouling control. This study investigated the filtration performance of ceramic membrane enhanced by the emerging titanium-based coagulant (polytitanium chloride, PTC). Particular attention was paid to the simulation of ceramic membrane fouling using four widely used mathematical models. Results show that filtration of the PTC-coagulated effluent using flat-sheet ceramic membrane achieved the removal of organic matter up to 78.0%. Permeate flux of ceramic membrane filtration reached 600 L/(m 2 · h), which was 10-fold higher than that observed with conventional polyaluminum chloride (PAC) case. For PTC, fouling of the ceramic membrane was attributed to the formation of cake layer, whereas for PAC, standard filtration/intermediate filtration (blocking of membrane pores) was also a key fouling mechanism. To sum up, cross-flow filtration with flat-sheet ceramic membranes could be significantly enhanced by titanium-based coagulation to produce both high-quality filtrate and high-permeation flux.
研究领域:
环境工程
·
水处理技术
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DOI
高影响因子
Separations
·
2022
·Vol. 9
·期 9
·241
·
IF 3.344
Yuanhui Tang,Wenwen Sun,Yakai Lin,Lin Wang,Hedi Chen,Huanhuan Wu,Lixin Yu,Xiaolin Wang
To achieve a cleaner production, pesticide wastewater with concentrated NaCl can be treated by using a bipolar membrane electrodialysis (BMED) and converted to NaOH and HCl, which minimizes acid and alkali consumption in a pesticide production process. However, ion-exchange membranes (IEMs) are vulnerable to fouling by phenolic substances present in the concentrated NaCl solutions. This work aimed to understand the performance and fouling mechanism of BMED from phenol during the desalination of NaCl and explore an effective cleaning method. The results firstly showed that for the NaCl solutions with higher phenol concentrations, the selectivity of the IEMs was reduced after processing six successive batches of BMED, which led to reverse migration of ions, organics leakage, and an obvious increase in the energy consumption and the concentration of generated acid and alkali. Secondly, IEMs characterization analysis detected that the structure of the IEMs was deformed, while phenol fouling deposits were observed on the surface and interior of the IEMs, especially for the anion exchange membranes (AEMs). Then, the results of soaking tests proved that the phenol could bring about swelling-like degradation to the AEMs and 0.1 wt.% NaOH solution was studied to be the optimized cleaning agent since the performance of the fouled IEMs in the short-running process could be recovered after 5 h of in situ cleaning that removed the phenol fouling deposits efficiently. Finally, the results of a long-running BMED operation treating NaCl solution containing 10 g/L phenol concentration showed that the IEMs were severely fouled, and the fouling was firstly due to the swelling-like mechanism during the initial 12 successive batches, and then should belong to the blockage-like mechanism during the following 20 successive batches. The seriously fouled IEMs could no longer be recovered even after a deep in situ cleaning. This research proves that under appropriate pretreatment or operating conditions, the BMED process is an alternative way of treating wastewater with high salinity and the presence of phenol molecules.
研究领域:
环境工程
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化学工程
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DOI
高影响因子
JOURNAL OF POWER SOURCES
·
2024
·
IF 8.1
Hongsheng Liu,Hengyue Li,Bin Huang,Yange Yang,Haibo Guo,Yan Xiao,Weiguang Yang
To enhance the proton conductivity and durability of Ce-based hybrid proton exchange membranes (PEMs), this study fabricates modified perfluorosulfonic acid (PFSA) hybrid membranes by incorporating the dual-function γ-AlOOH@Ti-supported CeO 2 composite oxide (γ-AlOOH@Ti/CeO 2 ). In addition to combining the inherent proton conductivity of γ-AlOOH with the excellent radical scavenging ability of CeO 2 , both the proton conductivity and durability of Ce-based PEMs are further improved by introducing Ti-dopant, which not only increases hydrogen vacancies on the surface of γ-AlOOH, which facilitate proton conduction, and induces electron transfer from γ-AlOOH@Ti to CeO 2 , which enhance free radical adsorption. As results shown, the proton conductivity and the fluoride release value of the resulting hybrid membrane are about 76 % higher and 35.25 % lower than those of the PFSA-CeO 2 membrane, respectively. Moreover, the performance of cells shows that, after accelerated degradation testing, the PFSA-γ-AlOOH@Ti/CeO 2 membrane exhibits the lowest peak power density decrease rate, the impedance increase rate and hydrogen crossover current density, with 11.79 %, 27.54 % and 3.04 mA cm −2 , respectively. These results suggest that compared to CeO 2 -hybrid PEMs, γ-AlOOH@Ti/CeO 2 -based hybrid PEMs exhibit higher proton conductivity and superior chemical stability, indicating the potential application of γ-AlOOH@Ti/CeO 2 -based hybrid PEMs in proton exchange membrane fuel cells.
研究领域:
材料科学
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能源化学
·
电化学
✓ 已验证
DOI
高影响因子
Desalination and Water Treatment
·
2024
·
IF 1
Chabi Noël Worou,Jing Kang,Taofic Bacharou,Jimin Shen,Pengwei Yan,Arcadius Degan,Yingxu Gong,Razack Guene,Zhonglin Chen
A single dual thin-film titanium-zirconium as selective layers membrane for divalent and monovalent ions removal was fabricated. Both dioxide of titanium (TiO 2 ) and dioxide of zirconium (ZrO 2 ) have been co-deposited on an ultrafiltration polyacrylonitrile membrane using information given by scanning electron microscopy (SEM) combined with energy-dispersive X-ray spectroscopy (EDS). The important insights provided by SEM associated with EDS on the arrangement and potential functions of nanoparticles (NPs) due to their unambiguous chemical signal were used for characterization and modification of membrane surface at an atomic scale. Thus, a novel thin-film composite-nanofiltration membrane (TFC-NFM) has been performed for the first time. The new-born organic–inorganic membrane NF-TiZr exhibited excellent performance rejection towards monovalent ions and its rejection rate for multivalent ions reached 95%. The order of salts rejection was CaCl 2 > MgSO 4 ~ MgCl 2 > NaCl > Na 2 SO 4 . The permeate flux of the NF-TiZr membrane is as high as 58 L m –2 h –1 . 180 h-continuous exploitation of NF-TiZr showed a slight variation of permeate flux less than 1.2% and the salt rejection remained high than 92.5% at the end of the operation. To our best knowledge, it is the first time SEM was combined with EDS to help for optimal co-deposition of nanoparticles on the membrane surface. This study may provide useful insights to design next-generation NFMs.
研究领域:
环境科学
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材料科学
·
化学工程
✓ 已验证
DOI
高影响因子
Bioresource Technology Reports
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2021
·
IF 0
Mister Adeel,Yubo Xu,Long-Fei Ren,Jiahui Shao,Yiliang He
Extractive membrane bioreactor (EMBR) is a promising technology for phenol saline wastewater treatment . In this work, an electrospun polydimethylsiloxane/polymethyl methacrylate/multi-walled carbon nanotubes (PDMS/PMMA/MWCNTs) membrane was firstly used in EMBR. To address low phenol transmembrane mass transfer issue, effects of wastewater condition (1.3–5.5 L/h circulation rate , 1000–4000 mg/L phenol), biomass addition (without/with pre-acclimated activated sludge) and biofilm formation (50.5–120.7 μm) were investigated. Membrane characterizations confirmed that biofilms on membrane surface gradually developed under increasing phenol concentrations, with simultaneously increased thickness and extracellular polymeric substances (EPS) excretion. Results showed phenol transmembrane mass transfer rates with activated sludge and formed biofilm increased 21.6–31.7% compared to those without activated sludge. Finally, 100% removal of permeated phenol and 99.96% rejection of salt were achieved under wastewater circulation rate of 4.4 L/h with 1000–4000 mg/L phenol and 10 g/L sodium chloride. Relevant findings are of significance in promoting the EMBR application in organic-inorganic composite wastewater treatment.
研究领域:
环境工程
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膜技术
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废水处理
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生物技术
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DOI
Nano Select
·
2021
·Vol. 2
·期 7
·1403-1416
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IF 0
Bin Yang,Yang-nan Yu,Yang Pan,Shu-qing Wang,Xiang Xu,Ying-ying Wang,Jia-sheng Qian,Ru Xia,Peng Zhang,You Shi,You-lei Tu
In this research, series of PVDF microporous films with various polymer concentrations and thickness were prepared through thermally-induced phase separation in air condition with diphenyl carbonate as the diluent. Effects of polymer concentration and film thickness on the formation kinetics of microporous structure of PVDF thin films were in situ investigated via TII technique. The instantaneous heat conduction inside the films during film formation was also evaluated. Two types of parameter models were adopted in order to disclose the time and location dependence of TIPS film solidification kinetics, respectively. Hierarchical microstructures, crystallization behavior and thermal properties of the TIPS films were also characterized by SEM, DSC, and TGA, respectively. The current study could supply an insight into the fabrication of PVDF microporous films with target microstructure and desirable performance.
研究领域:
材料科学
·
高分子化学
·
膜科学技术
✓ 已验证
DOI
Advanced Membranes
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2024
·
IF 0
Junqi Ning,Cailin Yang,Qiuyu Mei,Limingming Huang,Kai Han
ABSTRACT The practical use of solar-driven interfacial evaporation is hampered by high cost, low photothermal conversion efficiency, and poor stability. Herein, a one-dimensional Fe/C constructed photothermal membrane is rationally developed to replace precious metals via the combination of Fe plasmon resonance with carbon molecular thermal vibration. The membrane exhibits excellent light absorbance (95.72%) and water evaporation rate (2.60 kg·m -2 ·h -1 ) leading to photothermal conversion efficiency up to 95.65% under 1 sun illumination. Janus Fe/C membrane with superhydrophobic and hydrophilic structure is further prepared by polydimethylsiloxane (PDMS) coating to improve long-term stability. The evaporation rate can be maintained at over 90% after 80 h illumination for real seawater treatment with metal ion removal efficiency >99%. It also shows high evaporation performance and stability for organic solvents such as IPA, and NMP. Thus, the 1D Fe/C constructed Janus membrane is a promising candidate for energy-saving solar-driven interfacial solvent evaporation including seawater desalination, wastewater treatment, and organic solvent purification.
研究领域:
材料科学
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能源工程
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环境工程
✓ 已验证
DOI
JOURNAL OF MEMBRANE SCIENCE
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2018
·
IF 6.578
Lihao Xu,Yang He,Xia Feng,Fengying Dai,Ning Yang,Yiping Zhao,Li Chen
In the separation of oil/water emulsions using membrane separation methods, fouling remains a problem. To improve the fouling resistance effectively, a hydrophilic tannic acid (TA) coating was constructed on the poly(vinylidene fluoride) (PVDF) membrane via dip-coating method. Both the wettability and surface free energy were dramatically enhanced after the introduction of the TA coating. TA deposition with extended dip-coating time did not result in a corresponding increase in the pure water permeate quality, suggesting that there is a trade-off between the enhanced surface hydrophilicity and diminished pore size. Furthermore, the threshold fluxes were determined using the flux-stepping method, and explored to provide guidance on membrane fouling rates for oil/water emulsion filtration. The hydrophilic TA dip-coated PVDF membrane prepared at a dip-coating time of 9 h exhibited the highest threshold flux compared to the other membranes. The experimental evidences of the threshold fluxes can be used to predict the sustainable flux regimes for the TA dip-coated membranes. Constant flux verifiable experiments for oil/water emulsion were performed at fluxes near and below the threshold fluxes. By selecting a constant flux strategy below the threshold flux, membrane over-fouling can be avoided efficiently and the operating period can be prolonged favourably. More generally, operation below the threshold flux recognizes a modest fouling level, arising from the sufficient flux, which would result in the infrequent need for cleaning and is a compromise between capital expenditure and operating costs.
研究领域:
环境工程
·
材料科学
✓ 已验证
DOI
高影响因子
JOURNAL OF MEMBRANE SCIENCE
·
2020
·
IF 7.183
Zhong Ma,Guiming Shu,Xiaolong Lu
Excellent antifouling membrane surfaces and membrane cleaning efficiency are immensely desired but challenging to achieve. In this study, we initially prepared pH-responsive hydrophilic membrane surfaces by introducing carboxyl groups onto polyvinylidene fluoride (PVDF) membrane surfaces via amine group bridging. Then, partial perfluoroalkylation modification was performed through an amidation reaction between the carboxyl groups on the hydrophilic membrane surface and amine groups of fluorinated diamine. Therefore, a membrane surface with a discontinuous amphiphobic fluorine island structure was successfully fabricated. Experimental results for soybean oil/water emulsion separation demonstrated that compared with hydrophilic-modified membrane (PVDF–MAH), the stable flux of fluorine island-modified membrane (PVDF–PFOA) increased by approximately 67%. Moreover, compared with the PVDF–MAH membrane, the flux of the PVDF–PFOA membrane at the end of the fourth filtration cycle (i.e., before chemical cleaning) increased by approximately 34% and its flux recovery rate at the beginning of the fifth filtration cycle (i.e., after chemical cleaning) increased by approximately 6%. The as-prepared membrane with fluorine island structure facilitates a new effective method for solving the membrane fouling problem during practical applications of membrane technology .
研究领域:
材料科学
·
环境工程
✓ 已验证
DOI
高影响因子
JOURNAL OF MEMBRANE SCIENCE
·
2021
·
IF 8.742
Yan Wang,Jingyu Zhang,Chunyang Bao,Xiaoling Xu,Die Li,Jing Chen,Mei Hong,Bin Peng,Qiang Zhang
Novel self-cleaning catalytic membranes are prepared for water treatment via an integration of heterogeneous Fenton and membrane process. Polysulfone (PSF) based functional copolymers with pendant ferrocene groups are facilely synthesized via a combination of controlled radical polymerization and ester coupling reaction. Different catalytic membranes with tuned surface hydrophilicity are then prepared through non-solvent phase inversion method based on functional ferrocene- and hydroxyl-containing PSF. These membranes have demonstrated high activity in catalyzing Fenton-type reactions, which also lead to outstanding antifouling performance for the membrane. Finally, the catalytic membranes are successfully used for treatment of waste water containing different dyes. The proposed strategy in this work may provide worthy guidance to catalytic membranes, which is promising for water purification through simultaneous Fenton reaction and membrane separation .
研究领域:
环境科学
·
材料科学
✓ 已验证
DOI
高影响因子
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
·
2022
·
IF 4.326
Huimin Ruan,Lu Yu,Yuyang Yao,Junhua Li,Jianlang Yan,Junbin Liao,Jiangnan Shen
The development of antifouling ion exchange membranes (IEMs) is of great significance to the application of electrodialysis (ED). Membrane fouling is a ticklish question affecting the membrane performance, which results in an increase in energy consumption in ED and unnecessary economic loss. In this work, we report poly(vinyl alcohol) (PVA) as an IEM substrate; a large number of hydroxyl groups on the aliphatic chain react with a small rigid molecule of 4-(bromomethyl)benzaldehyde (QBMB) prepared by us and then adjust the time of quaternization by trimethylamine to design a series of antifouling anion exchange membranes (AEMs) named PVA-QBMB-X (X = 2, 4, 6, and 12). The as-prepared AEMs with a cross-linking structure within the matrix exhibit low surface area resistance and reduced swelling ratios of <16.2%. The optimized PVA-QBMB-12 AEM shows better antifouling performance in terms of a much longer transition time (1150 min) than commercial membrane AEM-Type-II (620 min) by possessing excellent hydrophilicity and superior ED performance compared with the commercial membrane. The optimized AEM shows a superior NaCl removal rate of 99.80 ± 1.5%, a current efficiency of 82.64 ± 0.8%, and an energy consumption of 2.98 ± 0.3 kWh kg–1 NaCl, which are better than those of AEM-Type-II (97.51 ± 1.5, 76.26 ± 0.7%, and 4.54 ± 0.6 kWh kg–1 NaCl, respectively). Thus, the investigation demonstrates the potential application of the as-prepared AEMs for ED in organic pollutant systems.
研究领域:
材料科学
·
环境工程
✓ 已验证
DOI
高影响因子
JOURNAL OF APPLIED POLYMER SCIENCE
·
2012
·Vol. 127
·期 6
·4564-4572
·
IF 1.289
Wan-Zhong Lang,Qin Ji,Jian-Ping Shen,Ya-Jun Guo,Lian-Feng Chu
The modified poly(vinylidene fluoride) (PVDF) hollow fiber composite membranes reinforced by hydroxyapatite (HAP) nanocrystal whiskers were fabricated with wet-spinning method. The PVDF/HAP/ N -methyl-2-pyrrolidone dope solutions experienced delayed demixing mechanism, and the precipitation rate slightly increased as the HAP whisker content increased. The cross sections of PVDF-HAP and neat PVDF hollow fiber composite membranes were composed of five distinct layers: two skin layers, two finger-like sublayers, and a sponge-like layer. The Young's modulus of and tensile strength of the PVDF-HAP hollow fiber membranes gradually increased with the addition of nano-HAP whiskers. The elongation ratio was also improved, which was different from the polymeric membranes modified by other inorganic nanofillers. The permeation flux of the PVDF-HAP hollow fiber membranes slightly increased with the increase of HAP content in the composite membranes as its hydrophilicity was improved. The crystallization behaviors of PVDF in the composite membranes were also investigated. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
研究领域:
材料科学
·
生物医学工程
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）