Membranes
·
2022
·Vol. 12
·期 11
·1071
·
IF 4.562
Huali Tian,Xing Wu,Kaisong Zhang
To enhance the permeation and separation performance of the polyethersulfone (PES) tight ultrafiltration (TUF) membrane, two-dimensional molybdenum disulfide (MoS2) was applied as a modifier in low concentrations. The influence of different concentrations of MoS2(0, 0.25, 0.50, 1.00, and 1.50 wt%) on TUF membranes was investigated in terms of morphology, mechanical strength properties, permeation, and separation. The results indicate that the blending of MoS2tailored the microstructure of the membrane and enhanced the mechanical strength property. Moreover, by embedding an appropriate amount of MoS2into the membrane, the PES/MoS2membranes showed improvement in permeation and without the sacrifice of the rejection of bovine serum protein (BSA) and humic acid (HA). Compared with the pristine membrane, the modified membrane embedded with 0.5 wt% MoS2showed a 36.08% increase in the pure water flux, and >99.6% rejections of BSA and HA. This study reveals that two-dimensional MoS2can be used as an effective additive to improve the performance and properties of TUF membranes for water treatment.Keywords:tight ultrafiltration membrane;molybdenum disulfide;humic acid rejection;BSA rejection
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
Journal of Water Process Engineering
·
2025
·
IF 6.7
Peigen Zhou,Haoyu Zhang,Yingdong Chen,Rongze Sun,Wentao Yan,Yong Zhou,Congjie Gao
Safe water is vital to human health. NF membrane technology has been demonstrated to be an effective solution for the remediation of water contamination in the environment. Polyvinyl alcohol (PVA) is one of the most promising materials for preparing NF membrane. The traditional PVA membrane preparation usually relies on sulfuric acid as a catalyst for crosslinking. However, strong acid raises safety and environmental concerns. In this study, we propose an acid-free cross-linking strategy to address the issue and improve the membrane flux simultaneously. Specifically, the cross-linking is achieved via the reaction between 4,4′-diaminodiphenyl sulfone and epoxy group which is grafted onto the PVA backbone. The epoxy group could reduce the crystallinity of PVA by disrupting its structure and then induce the improvement of membrane flux. The results showed that the flux was improved to 46.7 L·m −2 ·h −1 ·bar −1 and meanwhile the dye rejection was retained at high level (>96.79 %). Besides, in order to improve the salt rejection, the adsorption-enhanced membrane separation method was applied. An absorbent, acrylic acid-2-acrylamide-2-methylpropanesulfonic acid copolymer (AA-AMPSA), was added into the feed solution. Because salts were adsorbed by AA-AMPSA, which is big and could be rejected by the membrane, the rejection was improved. Due to the usage of AA-AMPSA, the salt rejection of the prepared membrane can reach a high level (98.5 %). This work provides new ideas to enhance the performance of PVA NF membrane and helps to promote the development of NF membrane technology for efficient wastewater treatment.
研究领域:
环境科学
·
膜分离技术
·
高分子材料
·
水处理工程
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
Membranes
·
2023
·Vol. 13
·期 9
·759
·
IF 4.2
Fanxin Kong,Lian You,Dingwen Zhang,Guangdong Sun,Jinfu Chen
Polysulfone (PSf) membranes typically have a negligible rejection of salts due to the intrinsic larger pore size and wide pore size distribution. In this work, a facile and scalable heat treatment was proposed to increase the salt rejection. The influence of heat treatment on the structure and performance of PSf membranes was systematically investigated. The average pore size decreased from 9.94 ± 5.5 nm for pristine membranes to 1.18 ± 0.19 nm with the increase in temperature to 50 °C, while the corresponding porosity decreased from 2.07% to 0.13%. Meanwhile, the thickness of the sponge structure decreased from 20.20 to 11.5 μm as the heat treatment temperature increased to 50 °C. The MWCO of PSf decreased from 290,000 Da to 120 Da, whereas the membrane pore size decreased from 5.5 to 0.19 nm. Correspondingly, the water flux decreased from 1545 to 27.24 L·m−2·h−1, while the rejection ratio increased from 3.1% to 74.0% for Na2SO4, from 1.3% to 48.2% for MgSO4, and from 0.6% to 23.8% for NaCl. Meanwhile, mechanism analysis indicated that the water evaporation in the membranes resulted in the shrinkage of the membrane pores and decrease in the average pore size, thus improving the separation performance. In addition, the desalting performance of the heat-treated membranes for real actual industrial wastewater was improved. This provides a facile and scalable route for PSf membrane applications for enhanced desalination.Keywords:PSf membrane;heat treatment;rejection 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
Journal of Water Process Engineering
·
2022
·
IF 7.34
Chuanfeng Wang,Yingbo Chen,Xiaoyu Hu,Pengfei Guo
A dual-layer (DL) PVDF loose nanofiltration (NF) hollow fiber membrane (HFM) with desirable properties was designed via phase inversion process using a continuous online-coating device. By fine-tuning dope formulation and fiber formation, the PVDF coating layer with NF separation capabilities was formed on the shell side of porous matrix-reinforced hollow fiber support while making fiber continuously. The effects of several parameters (e.g., LiCl content, co-solvent ratio (i.e., DMAc:THF) and air-bath distance (evaporation time)) on structures and properties were investigated to manipulate membrane MWCO . It was found that the introduction of volatile co-solvent and the control of evaporation time helped to significantly reduce the PVDF selective layer's thickness. The structure along with performance of the HFM demonstrated the DL ultrafiltration (UF) HFM could be successfully converted into NF HFM only by adjusting the parameters in the production system. After optimizing both phase inversion parameters and coating conditions, the resultant loose NF HFM presented a low MWCO of 1530 Da and a high pure water flux (PWF) of 14.2 L·m −2 ·h −1 ·bar −1 . Meanwhile, the HFM showed competitive dyes rejection (i.e., 99.9% for Rose bengal and Eriochrome black T, 96.5% for Methylene blue) and low NaCl rejection (3.2%). Furthermore, the prepared membrane also presented good stability and high flux recovery during a continuous NF process. This work provided a simple and economical strategy for engineering scalable loose NF HFM for dye purification.
研究领域:
膜科学
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环境工程
·
水处理
·
材料科学
✓ 已验证
DOI
高影响因子
JOURNAL OF MEMBRANE SCIENCE
·
2020
·
IF 7.183
Jieyu Hu,Meng Li,Lianjun Wang,Xuan Zhang
Conventional graphene oxide (GO) desalination membranes generally experience severe structural deterioration due to physical swelling. The strong surface negativity of the membrane also synchronously influences the diffusion/transport behaviors of all the solutes, leading to a low solute-solute selectivity. To address these issues, a novel poly (styrenesulfonic acid- co -4-vinylpyridine) brush-modified GO nanosheet (PB-GO) is designed and synthesized via atom transfer radical polymerization (ATRP) and is then employed to fabricate the GO membranes by a vacuum filtration approach, followed by chemical crosslinking with glutaraldehyde (GA). The sulfonate groups of the polymer enable excellent water dispersibility, while the pyridine groups are locally protonated under appropriate conditions, leading to the neutralization of the surface charge of the PB-GO nanosheets. The best performing membrane had a PB-GO mass loading of 0.3 g m −2 (PB-GO-0.3). In addition to a high water permeability of 30.3 ± 4.2 L m −2 h −1 bar −1 , this membrane also exhibits ultralow rejection of Na 2 SO 4 (<6.9%) over a wide concentration range (1.0–20.0 g L −1 ) in a cross-flow operation mode, due to the suppressed charge repulsion effect. However, the typical dye molecules, e.g. Congo red, direct red 23, and direct red 80, could be effectively rejected (>98.3%) based on the size exclusion effect. As a result, the PB-GO-0.3 membrane provides a high solute-solute selectivity of 58.18, which far exceeds that of commercial and other reported nanofiltration membranes. Overall, we provide a facile strategy for designing a polymer brush-functionalized GO membrane for effective dye/salt fractionation to treat textile wastewater.
研究领域:
材料科学
·
环境工程
·
膜技术
·
水处理
✓ 已验证
产品关联
DOI
高影响因子
DESALINATION
·
2024
·
IF 8.3
Fan-xin Kong,Shi-yuan Zhang,Ding-wen Zhang,Ping Xia,Jin-fu Chen
Construction of covalent organic frameworks (COF) membranes on the polymeric substrate was challenging by interfacial polymerization (IP) process. In this study, COF-LZU1 membranes were fabricated by IP on the preheated PSf substrates to investigate the influence of substrate properties (i.e., pore size and porosity) on the COF-LZU1 layer formation. The substrates with tunable pore size (18.61 to 14.53 nm) and porosity (2.05 % to 0.42 %) could be obtained with the pretreating temperature of 20 °C to 50 °C. Preheated substrate altered monomer storage and diffusion, leading to the variations in crosslinking degree (14.89 % to 87.63 %) and observed thickness (142.9–575.9 nm). The preheated substrates endowed better growth conditions by inhibiting the COF-LZU1 intrusion into the substrates, and optimal COF 40°C membrane had water flux of 6.57 L m −2 h −1 , and Na 2 SO 4 rejection ratio of 90.9 %. The rejection ratio of pharmaceuticals by COF-LZU1 membranes was low due to adsorption. Correlation analysis showed that the C N bond content was unfavorable for absorption ( P < 0.05), and the increase of crosslinking and crystallinity of the COF-LZU1 layer will be beneficial to boost the pharmaceutical rejection. This work provided a facile method and valuable insight for the COF-LZU1 membrane fabrication to enhance desalination and pharmaceutical removal.
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
DESALINATION
·
2022
·
IF 11.211
Xiumin Zhang,Yongping Dong,Qingyi Wang,Hang Yu,Congjie Gao,Lixin Xue
Structures and NF performance of TFC-Co and TFC membranes activated with 50 % alcohol solutions were studied. Methanol and glycol solution activation increased water flux 2–4 times without trading off salt rejection while glycerin solution activation increased water flux 3–4 times with reduced salt rejection and increased dye/salt retention selectivity . The Stokes radius of TFC-Co membrane changed from 0.77 nm to 0.66, 0.78 and 0.92 nm while the TFC membrane changed from 0.54 nm to 0.55, 0.65 and 0.70 nm after activation with methanol, glycol and glycerin solutions, respectively. Capillary pore filling models were developed from pure alcohol absorption experiments including the stages of initial pore filling, pore expansion, pore relaxation and pore adjustment, while most Stokes radius after 50 % solutions activation were found to be close to the relaxed pore radius values (r rx ) or half of the expanded pore radius values (r ex ) from pure alcohol absorption experiments.
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
APPLIED SURFACE SCIENCE
·
2020
·
IF 6.182
Jing Ren,Jianfeng Li,Zhaozan Xu,Yu Liu,Fangqin Cheng
To overcome the limitations of existing hydrophobic membranes for membrane distillation (MD) to treat industrial wastewater with complex contaminants, a composite membrane was developed in this study via incorporating graphene oxide (GO) on commercial polytetrafluoroethylene (PTFE) membrane. The dual-layer GO/PTFE membrane demonstrated asymmetric wettability, which transformed the membrane from in-air hydrophobic and underwater superoleophilic pristine surface to in-air hydrophilic and underwater oleophobic surface. The composite membrane displayed excellent salt rejection (>99.9%) and organic rejection (99.4%) during MD of bio-treated coking wastewater, outperforming the pristine PTFE membrane with apparent fouling and wetting phenomenon. The flux of GO/PTFE membrane reached 20.1 kg/m 2 ·h, which is 44% higher than that of the pristine membrane. These improvements were attributed to the specific morphological and physicochemical characteristics of the composite membrane, such as high water affinity, strongly negative charges on membrane surface, reduced temperature polarization and screening effect to large molecules by the GO layer. This study suggests that GO/PTFE composite membrane has great potential in enhancing the permeate flux and fouling resistance simultaneously, which could be a competitive option for MD to treat challenging wastewaters enriched with salts and hydrophobic organics.
研究领域:
环境工程
·
水处理
·
膜技术
✓ 已验证
产品关联
DOI
高影响因子
ACS ES&T Water
·
2021
·
IF 0
Wenzhong Ma,Xinlei Dai,Pei Qiu,Hanwen Ye,Jing Zhong,Hideto Matsuyama
The performance of a cross-linked polyimide (PI) nanofiltration membrane was assessed by interfacial polymerization (IP) combined with the chemical imidization method. With the IP process with m-phenylenediamine and pyromellitic chloride monomers, trimesoyl chloride (TMC) for cross-linking, and the subsequent chemical imidization process, a PI thin film composite (TFC) nanofiltration (NF) membrane was prepared. The results showed that the PI TFC membrane had a high flux of ∼9.13 L m–2 h–1 bar–1 at 4 bar. The effects of the amount of cross-linking agent and reaction time on the NF membranes’ nanofiltration performance were systematically investigated. We selected a CaSO4 salt solution to evaluate the performance of the nanofiltration membrane because the PI TFC nanofiltration membrane’s molecular weight cutoff was in the range of 600–800 Da. The PI membrane rejection to CaSO4 aqueous solution under the optimal preparation conditions reached 93%. When the FCF/water, FCF/DMF, and FCF/ethanol solutions were filtered, the TMC cross-linked PI TFC membrane exhibited a <8% solvent permeation decline but FCF rejection remained at 98%. The PI TFC membrane maintained permeability and salt rejection during the 120 h filtration.
研究领域:
材料科学
·
环境工程
✓ 已验证
DOI
CHINESE JOURNAL OF CHEMICAL ENGINEERING
·
2016
·
IF 1.207
Cunyu Li,Yun Ma,Hongyang Li,Guoping Peng
With the rapid increase of water contamination, membrane separation technology and their corresponding molecular weight cut-off (MWCO) evaluation method become more necessary. In this study, Panax notoginseng saponins was used as a new standard marker to determinate ultrafiltration (UF) membrane MWCOs, series of Millipore membranes were selected as control group to analyze and calculate the relationship between retention rate and MWCOs with exponential or logarithmic equation. A new and convenient method was provided for determining the membrane MWCO by modeling analysis retention rate with MWCOs, and the regression coefficients ≥ 0.990. The feasibility and practicability of established method was verified by different manufactures' membrane and dextrans . In the detection progress, as the main ingredient of Panax notoginseng saponins , Notoginsenoside R 1 , Ginsenoside Rg 1 , Ginsenoside Rb 1 and Ginsenoside Rd with different surface activity, the MWCO range of UF membranes can be divided into two zones mainly due to the retention rate difference among Notoginsenoside R 1 , Ginsenoside Rg 1 , Ginsenoside Rb 1 and Ginsenoside Rd . Zone I, 1000–10000; and Zone II, 10000–100000. Thus, the new method would be helpful to improve the applicability of UF membrane in separation technology.
研究领域:
环境科学
·
药学
✓ 已验证
DOI
高影响因子
JOURNAL OF MEMBRANE SCIENCE
·
2021
·
IF 8.742
Huimin Zhou,Xuesong Li,Yang Li,Ruobin Dai,Zhiwei Wang
A nanofiltration (NF) membrane capable of efficiently separating dye and salt at high-salinity is of great interest for the effective treatment of the textile wastewater. However, existing NF membranes exhibit either an excessively high salt rejection or a compromised dye rejection at high salinity. To overcome these challenges, herein the highly uniform nanovesicles functionalized with positively-charged molecules and nonreactive polymers were employed to tune the surface charge density and pore size of the thin-film composite (TFC) NF membrane via interfacial polymerization. The tuning proved efficient to simultaneously reduce surface charge density and enlarge pore size to the desired extent, which enabled a very low retention of salts (∼7% for NaCl) while maintaining a rather high dye rejection (∼99.8% for Direct red 23) with a high salt/dye separation factor of 464. Additionally, the separation stability of the finely-tuned membrane was superior to most of other reported NF membranes when treating a high-salinity dye/salt mixture. Meanwhile, the water permeability of the modified TFC membrane was enhanced by a factor of 2.6, reaching up to 205.8 L m −2 h −1 MPa. This study paves a new route to the high-performance NF membrane for an effective treatment of the high-salinity textile wastewater.
研究领域:
环境工程
·
膜科学
·
水处理
✓ 已验证
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2021
·
IF 13.273
Yan-Li Ji,Hong-Hao Lu,Bing-Xin Gu,Run-Feng Ye,Yong Zhou,Quan-Fu An,Cong-Jie Gao
The widespread occurrence of organic micropollutants (OMPs) in water has serious effects on the environment and human health. Recently, reverse osmosis (RO) membrane technology has been used for resolving this emerging concern, and the state-of-the-art polyamide RO membranes are normally fabricated by the interfacial polymerization method. Further reducing the energy consumption and operation cost, developing high-performance polyamide RO membranes will be the key for resolving the issue of effective removal of OMPs. Herein, a new strategy is proposed for fabricating robust and high-efficient polyamide RO membranes via the self-assembled aromatic nanoparticles (SANs) controlled interfacial polymerization (SANCIP) method. The membrane surface characteristics and interior microstructures of polyamide layer could be conveniently manipulated by regulating the SAN nanoparticles size and content. The SANs tuned polyamide membrane (PAM-SAN) with asymmetric structure, e.g., much looser and crumpled front surface and much denser and smooth rear surface, exhibits ultra-high water flux ~ 67.8 L∙m −2 ∙h −1 and satisfactory NaCl rejection (>98.3%), as well as very high OMPs rejection (>99.4%). Moreover, the PAM-SAN membrane has good stability and anti-fouling performance in long-term RO running process. This facile and cost-effective strategy provides a useful guideline in designing high-performance polyamide membranes with a vast potential in the removal of OMPs for advanced water treatment.
研究领域:
水处理
·
膜科学
·
环境工程
·
纳米技术
✓ 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）