DESALINATION
·
2020
·
IF 7.098
Jiayu Tian,Hailin Chang,Shanshan Gao,Ruijun Zhang
The potential toxicity of heavy metals arising from the discharge of industrial wastewater has become a serious public concern. Fabrication of a thin film composite (TFC) NF membrane with desirable rejection of heavy metal ions is an attracting route to solve this problem. Hereon, we proposed a facile strategy for fabricating a TFC NF membrane with excellent heavy metal removal. The ratio of PIP and TMC was greatly enlarged by decreasing the concentration of TMC to an exceptional low extent. Thus a polyamide film with weak electronegativity and small pore size was successfully constructed on an ultrafiltration substrate membrane. Comprehensive characterizations were adopted to reveal the micro-variation of the resulted NF membranes when regulating TMC concentration . The optimized membrane prepared only with PIP and TMC can exhibit a high pure water permeability of 14.6 L m −2 h −1 bar −1 , desirable rejection of over 98% against Ni 2+ , Zn 2+ , Cu 2+ , and >92.7% against Cd 2+ . This performance could go beyond most of the reported candidates which were prepared with other complicated methods. The simplicity, low cost and scaling up feasibility of the current strategy is expected to well meet the requirements of industrial production of TFC NF membrane for heavy metal removal.
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
WATER SCIENCE AND TECHNOLOGY
·
2018
·Vol. 78
·期 8
·1733-1740
·
IF 1.247
Chen Lifang,Bian Xiaokai,Lu Xiaofeng
The performance of different nanofiltration (NF) membranes for the treatment of strontium-containing radioactive wastewater was investigated. The effects of the initial strontium concentration, solution pH and complexation phenomena on strontium removal were described. For all the three membranes, the strontium rejection increased with decreasing initial strontium concentration. Meanwhile, the strontium rejection was minimum at the membrane isoelectric point (pH 5) primarily due to decreased co-ion electrostatic repulsion. In the presence of a complexing agent (polyacrylic acid or ethylenediamine tetraacetic acid disodium salt), the strontium rejection was generally higher than those obtained without a complexing agent for NF 270 and XN 45. Membrane cleaning experiments were also conducted to recover the performance of the membranes, which exhibited degradation during long-time filtration. The performance of the membranes after cleaning was close to that of the virgin membranes, especially for XN 45, whose recovery percentage was nearly 100%.
研究领域:
核化学与放射化学
·
环境工程
·
膜分离技术
✓ 已验证
DOI
高影响因子
JOURNAL OF COLLOID AND INTERFACE SCIENCE
·
2025
·
IF 9.7
Wan-Long Li,Jia-Hui Xin,Ping Fu,Wan-Ting Lin,Zi-Lu Zhang,Xiao-Wei Luo,Zhi-Kang Xu,Ling-Shu Wan
Thin-film composite (TFC) nanofiltration (NF) membranes have been widely used for ionic/molecular separation. However, traditional NF membranes are limited by the unstable structure under high temperature, which leads to deteriorated separation performance. Herein, we report a secondary interfacial polymerization strategy to fabricate NF membranes with superior thermal stability from the conventional monomers. NF membranes after secondary polymerization possessed thicker and negatively charged polyamide layers. The secondary polymerization consumed partial residual acyl chloride groups and improved the compactness and structural stability of the polyamide layer. Molecular dynamics simulations further proved less polymer chain mobility of the polyamide segments after the secondary polymerization. The dense and thermostable NF membranes showed high rejections to MgSO 4 and Na 2 SO 4 at 85 °C. The membranes also maintained excellent stability during temperature cycling and long-term high-temperature operations. The proposed method is promising for the fabrication of thermostable NF membranes by simultaneously adjusting the chemical and physical structure via secondary interfacial polymerization.
研究领域:
膜科学
·
高分子化学
·
分离技术
·
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
PubMed
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
ENVIRONMENTAL SCIENCE & TECHNOLOGY
·
2021
·
IF 9.028
Yuanmiaoliang Chen,Kang-Jia Lu,Wenxiao Gai,Tai-Shung Chung
Membranes with robust antiwetting and antifouling properties are highly desirable for membrane distillation (MD) of wastewater. Herein, we have proposed and demonstrated a highly effective method to mitigate wetting and fouling by designing nanofiltration (NF)-inspired Janus membranes for MD applications. The NF-inspired Janus membrane (referred to as PVDF-P-CQD) consists of a hydrophobic polyvinylidene fluoride (PVDF) membrane and a thin polydopamine/polyethylenimine (PDA/PEI) layer grafted by sodium-functionalized carbon quantum dots (Na+-CQDs) to improve its hydrophilicity. The vapor flux data have confirmed that the hydrophilic layer does not add extra resistance to water vapor transport. The PVDF-P-CQD membrane exhibits excellent resistance toward both surfactant-induced wetting and oil-induced fouling in direct contact MD (DCMD) experiments. The impressive performance arises from the fact that the nanoscale pore sizes of the PDA/PEI layer would reject surfactant molecules by size exclusion and lower the propensity of surfactant-induced wetting, while the high surface hydrophilicity resulted from Na+-CQDs would induce a robust hydration layer to prevent oil from attachment. Therefore, this study may provide useful insights and strategies to design novel membranes for next-generation MD desalination with minimal wetting and fouling propensity.
研究领域:
材料科学
·
环境工程
✓ 已验证
DOI
高影响因子
Polymers
·
2017
·Vol. 9
·期 4
·116
·
IF 3.364
Rengui Weng,Lihui Chen,Shan Lin,Hui Zhang,Hui Wu,Kai Liu,Shilin Cao,Liulian Huang
Presently, most nanofiltration membranes are prepared with non-biodegradable petrochemical materials. This process is harmful to the ecosystem and consumes a large amount of non-renewable energy. In this study, biodegradable and biocompatible antibacterial cellulose/chitosan nanofiltration membranes (BC/CS-NFMs) were fabricated and characterized for their mechanical strength, antimicrobial activity, salt and dye filtration performance, and polyethylene glycol (PEG) retention using Thermal gravimetric analysis (TGA), Field emission scanning electron microscopy(FE-SEM), Fourier transform infrared spectroscopy(FT-IR), and X-ray diffraction (XRD). The BC/CS-NFMs were obtained by the hydrolysis and carboxymethylation of dense cellulose/chitosan membranes (BC/CSMs). The tensile strength of the BC/CS-NFMs decreased as the chitosan content increased. In addition, the thermal stability and antibacterial ability of the BC/CS-NFMs improved. The pore size is less than 1 nm, and a spongy, layered structure is observed in the cross-sectional FE-SEM images. FT-IR analysis shows that a part of the hydroxyl in cellulose transforms to carboxymethyl during the hydrolysis and carboxymethylation of the BC/CSMs. No obvious changes can be observed in the cellulose and chitosan after the blend membrane formation from the XRD measurements. Based on the experimental results on the permeation and rejection of BC/CS-NFMs, different proportions of cellulose and chitosan nanofiltration membranes almost did not affect the water flux and rejection rate. The BC/CS-NFMs showed better water flux and a higher rejection rate in aqueous dye-salt solutions.Keywords:cellulose;chitosan;antibacterial activity;nanofiltration membranes
研究领域:
材料科学
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环境科学
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生物医学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Membranes
·
2021
·Vol. 11
·期 9
·705
·
IF 4.106
Kaifeng Gu,Sichen Pang,Yong Zhou,Congjie Gao
Nanofiltration (NF) is a separation technology with broad application prospects. Membrane fouling is an important bottleneck-restricting technology development. In the past, we prepared a positively charged polyethyleneimine/trimesic acid (PEI/TMA) NF membrane with excellent performance. Inevitably, it also faces poor resistance to protein contamination. Improving the antifouling ability of the PEI/TMA membrane can be achieved by considering the hydrophilicity and chargeability of the membrane surface. In this work, sodium chloroacetate (ClCH2COONa) is used as a modifier and is grafted onto the membrane surface. Additionally, 0.5% ClCH2COONa and 10 h modification time are the best conditions. Compared with the original membrane (M0, 17.2 L m−2h−1), the initial flux of the modified membrane (M0-e, 30 L m−2h−1) was effectively increased. After filtering the bovine albumin (BSA) solution, the original membrane flux dropped by 47% and the modified membrane dropped by 6.2%. The modification greatly improved the antipollution performance of the PEI/TMA membrane.Keywords:nanofiltration;sodium chloroacetate;modification;antipollution performance
研究领域:
材料科学
·
环境工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
DESALINATION
·
2023
·
IF 9.9
Qiu-Yu Zhu,Zi-Yun Xu,Jie-Han Fu,Jie Huang,Zhen-Liang Xu,Min Tong,En-Chao Li,Yong-Jian Tang
Currently, most nanofiltration membranes exhibit satisfactory separation performance on the anions or cations, and few membranes could concurrently separate anion and cation . Therefore, preparing nanofiltration membranes with excellent separation performance for both anionic and cationic ions remains a challenge. Herein, we have developed a series of nanofiltration membranes using conventional interfacial polymerization with different ratios of trimesoyl chloride (TMC) and piperazine (PIP) concentrations. In the interface polymerization process, the amine groups carried by PIP imparted a positive charge, while the hydrolysis of acyl chloride groups resulted in the generation of carboxylic acid groups that introduced a negative charge. The mix-charged nanofiltration membrane could be fabricated by varying PIP/TMC concentration ratios. The optimized membrane exhibited high rejection rates for bivalent ions (Na 2 SO 4 rejection of 96.6 %, MgCl 2 rejection of 93.0 %), and its selectivity for Mg 2+ /Li + mixed solution was improved significantly. This work provides a novel approach for the development of nanofiltration membranes capable of effectively separating mono-/divalent ions.
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2021
·
IF 7.312
Yang Qin,Hailiang Liu,Yumin Sun,Qinglin Huang,Wei Li,Kaikai Chen,Wei Shu,Changfa Xiao
In this research, a novel interfacial enhanced thin film composite nanofiltration (TFC NF) membrane with nail-fixed like surface structure and wave line like cross-section structure, good permeability and superior interfacial stability was prepared by interfacial polymerization (IP) on one-step in-situ aminated polyvinyl chloride (APVC) support layer. The effects of amination agent (triethylenetetramine, TETA) content on the support layers and the effects of the support layers with different degrees of amination on the performance of the TFC NF membranes were studied comprehensively. Furthermore, the interfacial bonding strength of the TFC NF membrane was explored by the inverse permeation test. It was concluded from the results that higher TETA content in casting solution led to the APVC membrane to form macroporous surface structure, thinner top skin layer and larger mean pore size. Meanwhile, more TETA molecules were grafted onto the PVC chains through nucleophilic substitution to participate in IP in a synergistic manner. Accordingly, the corresponding TFC NF membrane formed a nail-fixed like surface structure similar to semi-free-standing polyamide (PA) layer and wave line like cross-section structure with thinner and denser active layer. The water flux of the TFC NF membrane prepared with the optimized APVC membrane as the substrate membrane was increased by 395% at 0.6 MPa compared with the TFC NF membrane prepared with PVC membrane as the substrate membrane, while Na 2 SO 4 rejection did not sacrifice and increased by 3.48%, which manifested that unique structure was favorable to speed up the water transmission and effectively conquered the trade-off effect. Moreover, the representative TFC NF membrane prepared with optimized APVC membrane as the substrate membrane with strong covalent bond between support layer and active layer demonstrated superior interfacial stability in the short-term circulating inverse permeation test.
研究领域:
膜科学
·
化学工程
·
环境工程
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
Membranes
·
2021
·Vol. 11
·期 3
·200
·
IF 4.106
Ming Cai,Chunfang Xie,Huazhao Zhong,Baoming Tian,Kai Yang
Organic fouling in the nanofiltration (NF) process, which is a non-thermal technology to recover active components, is a critical problem limiting its applications. This study seeks to identify the anthocyanins on the NF membrane and explore their fouling mechanisms during concentration of blueberry extracts. Seven kinds of monomeric anthocyanins in foulants—delphinidin-3-O-galactoside, delphinidin-3-O-glucoside, delphinidin-3-O-arabinoside, cyanidin-3-O-galactoside, petunidin-3-O-galactoside, peonidin-3-O-glucoside, and malvidin-3-O-glucoside—were identified. Moreover, chalcone, myricetin derivative, and an unknown substance with [M+H]+at m/z 261.1309, which is the fragment ion corresponding to the break of glycoside bond of anthocyanins, were obtained. Interactions between anthocyanins and membrane made from polyamide were principally governed by the CH-π and π-π stacking of aromatic rings, the establishment of hydrogen bonds, and electrostatic interaction. This study will be helpful to further control fouling and choice of cleaning agents in concentration of anthocyanins-rich extracts.Keywords:anthocyanins;nanofiltration;fouling mechanisms;interactions;membrane
研究领域:
食品科学
·
生物化学
✓ 已验证
DOI
高影响因子
DESALINATION
·
2016
·
IF 4.412
Pengli Chen,Xiao Ma,Zhaoxiang Zhong,Feng Zhang,Weihong Xing,Yiqun Fan
Removing mixture salts from dye solutions using membrane technology still need to be improved for high dye rejection and low salt rejection. In this work, ceramic membrane with pore size of 1.5 nm presented a satisfactory desalination of dye solutions containing NaCl and Na 2 SO 4 compared with two commercial organic nanofiltration membrane elements (DK and DL). Effect of salt content, salt type, molar ratio of NaCl and Na 2 SO 4 , dye concentration and pH on performance of ceramic membrane for desalination of Eriochrome black T (EBT) were investigated. The results showed that dye rejection decreased by increasing salt content, dye concentration and solution pH. Compared with dye-NaCl solutions, a relative high flux and low rejection of dye were observed when treating dye-Na 2 SO 4 solutions. For the mixture salt-dye solutions, the flux, which was higher than that for the single salt-dye solutions, first increased then decreased with decreasing C NaCl /C Na2SO4 due to the change of structure of cake layer. Supper-molecule aggregates of EBT formed by hydrogen-bond is mainly responsible for the high rejection of EBT (> 99%) at acid conditions. The rejection of NaCl and Na 2 SO 4 was below 20% and 40%, respectively. These promising results demonstrates that the new ceramic membrane has a potential application in dye purification.
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
JOURNAL OF MEMBRANE SCIENCE
·
2021
·
IF 8.742
Ben-Qing Huang,Yong-Jian Tang,An-Ran Gao,Zuo-Xiang Zeng,Shuang-Mei Xue,Chen-Hao Ji,Chuyang Y. Tang,Zhen-Liang Xu
Heavy metals pollution is an urgent problem that seriously hazards human health and ecosystems. Herein, dually charged nanofiltration (NF) membranes were prepared via a facile modification with diethylenetriamine (DETA) after interfacial polymerization. More amine groups were imported after grafting and a polyamide layer with opposite charges was constructed. The as-prepared membranes had a pure water permeability of 17.0 L m −2 h −1 bar −1 and maintained ideal rejection for both Na 2 SO 4 (98.2%) and MgCl 2 (94.1%), illustrating dually charged property. In addition, the dually charged NF membranes had high rejection to a series of heavy metals, showing good application potential in heavy metals removal .
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
危险品化学品经营许可证（带存储）