CHEMICAL ENGINEERING JOURNAL
·
2014
·
IF 4.058
Lijuan Feng,Wenyu Wang,Ruiqi Feng,Shuang Zhao,Hongyu Dong,Shenglei Sun,Baoyu Gao,Qinyan Yue
Three species of aluminum coagulants mainly consist of mononuclear Al species (Al a ), medium polymeric species (Al b ) and colloidal species (Al c ) were prepared, separated and purified by organic solvent precipitation method. The effect of different Al species on coagulation performance and membrane fouling were investigated through the coagulation–ultrafiltration hybrid process. The influence of flocs characteristics were also studied to build the relation model between Al species coagulation and membrane fouling mechanisms. The results showed different Al species combined with humic acid (HA) in diverse ways feature distinct floc properties and membrane fouling. Al a coagulant had better UV 254 and dissolved organic carbon (DOC) removal efficiency. Furthermore, Al a and Al c were beneficial to form larger flocs with lower strength and looser structure, whereas Al b was prone to form small flocs with higher strength and compact structure. Ultrafiltration experiments indicated that Al b is the most effective Al species to alleviate membrane fouling.
研究领域:
环境工程
·
水处理技术
✓ 已验证
产品关联
DOI
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2018
·
IF 3.927
Yanni Liu,Zhi Wang,Song Zhao,Xiaochang Cao,Nan Li,Jixiao Wang,Shichang Wang
Impacts of substrate membrane storage conditions, which might have special significance in the industry and laboratory research of composite membranes, are rarely reported. Herein, the polysulfone ultrafiltration membrane was chosen as a typical substrate membrane and differences between substrate membranes stored in wet and dry conditions were discussed. An easy-operational hydrothermal pretreatment method was therefore proposed to regenerate the dry substrate membranes. The substrate membranes were heated in deionized water, and the pore morphology was significantly improved after the pretreatment. Three types of additives were applied to improve the effects of pretreatment and the effects of the hydrothermal pretreatment turned to be stronger as the concentration of the additive increased. Membrane structure parameters were investigated and the dry support membranes pretreated with 3.0% or 6.0% molar fraction ethanol displayed approaching structure parameters with wet membranes pretreated with the same conditions, which means the dry substrate membranes were successfully regenerated. Poly(vinylamine)-polysulfone composite membranes were prepared with polysulfone substrates before and after pretreatment, and tested by using CO 2 /N 2 (15/85 by volume) mixed gas. Composite membranes prepared with wet and dry polysulfone substrates pretreated with 3.0% molar fraction ethanol exhibited similar CO 2 permeance, which confirmed that the dry substrate membranes were effectively regenerated.
研究领域:
材料科学
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环境工程
✓ 已验证
产品关联
DOI
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
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2018
·
IF 3.927
Chunli Liu,Yuxuan Sun,Zhenbin Chen,Suobo Zhang
An integrally skinned dense ultrafiltration (UF) membrane was prepared using partially di-quaternized poly(sulfone- co -ethernitrile) random copolymer (PSF- co -DQAPEN) via classical nonsolvent induced phase inversion process (NIPS). Then the original UF membrane was molecularly restructured through a combined process of chemical quaternization-crosslinking reaction and thermal annealing for the preparation of a crosslinked nanofiltration (NF) membrane, in which p -xylylene dichloride (PXDC) and isopropanol were employed as crosslinking agent and nonsolvent treating medium, respectively. The influence of reaction time and crosslinker concentration on membrane performance were investigated. X-ray photoelectron spectroscopy (XPS) of membrane surface and solubility test of membrane were employed to study the chemical composition and crosslinking properties of membranes, and those results revealed that the original membrane had been successfully crosslinked after this post treatment process. The separation performance of membrane was ultimately changed from UF-level to NF-level after the quaternization-crosslinking reaction and thermal annealing treatment process. The optimum crosslinked NF membrane possessed MgCl 2 rejection of 98.2% and water permeate flux of 4.12 L m −2 h −1 bar −1 . Moreover, owning to the excellent chemical stability of membrane material, the crosslinked membrane had outstanding resistance to chlorine, acid and base, thus it can be used for water softening and removing of positive dyes. Given the convenience and feasibility of this modification method, integrally skinned NF membrane could be easily fabricated via the post chemical crosslinking and thermal annealing process of UF membrane using proper treating approaches.
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
CHEMICAL ENGINEERING JOURNAL
·
2016
·
IF 5.31
Hao Wu,Xiaojun Niu,Jia Yang,Caihong Wang,Meiqing Lu
The retention efficiencies of bisphenol A (BPA) and norfloxacin (NOR) by three different ultrafiltration (UF) membranes prepared in laboratory were investigated, together with the influencing factors such as initial concentration, ionic strength, pH, membrane fouling and trans-membrane pressure (TMP). The results show that the effects of initial concentration and ionic strength on retentions is minor for both BPA and NOR. BPA retentions substantially decreased as pH value approached to its p K a value, and for NOR they first increased and decreased afterwards with pH change. The retentions are all improved after HA fouling because of the HA block in the membrane pores and the developed cake layer, and it can be concluded that between pollutants and HA there exists not only adsorption with each other but also competitive adsorption for sites on membranes. The retentions of both BPA and NOR decrease with increasing pressure. Generally, the effects of these factors on BPA and NOR retention are different and the retentions of the three UF membranes for NOR always remain at a low level, which needs further investigation.
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
JOURNAL OF MEMBRANE SCIENCE
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2022
·
IF 10.53
Xuesong Ye,Jun Nan,Zhencheng Ge,Qiliang Xiao,Bohan Liu,Yujie Men,Jinyong Liu
Low-pressure ultrafiltration membrane (LPM) is an ideal technology for decentralized water supply. However, the applicability for removing ferrous iron (Fe 2+ ), manganese (Mn 2+ ), and ammonia (NH 4 + ) in the source water and related mechanisms remained unknown. To fill this major knowledge gap, we systematically compared the pristine (pr-LPM) and MnO 2 -preloaded membrane (Mn-LPM). Mn-LPM allowed higher water flux while enhancing the removal of Fe 2+ , Mn 2+ , and NH 4 + . The removal efficiency of Mn 2+ immediately reached 99.6% on the first day. The preloading of MnO 2 also enhanced the removal capacity of NH 4 + . A series of instrument characterizations suggest that a higher NH 4 + concentration resulted in a thicker bio-cake layer, correlating to the higher pollutant removal efficiency and the decrease in the stable flux. Under high NH 4 + concentrations, Anaerobic Ammonia Oxidation likely contributes to NH 4 + removal. These findings significantly improve the understanding and help the design of LPM systems for cost-effective decentralized water supply in remote areas.
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
SCIENCE OF THE TOTAL ENVIRONMENT
·
2022
·
IF 10.753
Kaizhen Wang,Shuhao Wang,Kaifeng Gu,Wentao Yan,Yong Zhou,Congjie Gao
Polyamic acid (PAA) is a flexible polymer and has abundant valuable hydrophilic groups. Herein, we developed an ultra-low pressure ultrafiltration (UF) membrane by integrating PAA into the polyethersulfone (PES) matrix via the “in-situ polycondensation” method. PAA was well compatible with PES and distributed uniformly in the membrane. The introduction of PAA improved membrane hydrophilicity. Meanwhile, the membrane pore structures were also refined. The membrane exhibited an excellent permeability under ultra-low pressure due to its improvement of hydrophilicity and pore structures. Under 0.3 bar, compare with the water flux of PES membrane, PES/PAA membrane improved nearly 2 times (571.05 L/(m 2 ·h)), with a high BSA rejection (≥90%). Even under a lower pressure, 0.1 bar, >300 L/(m 2 ·h) still can be achieved. Interestingly, the membrane we developed could maintain a high performance after drying, and then is very suitable for dry preservation. PES/PAA membrane showed a high oil removal (≥92%) and could remove oil from water effectively. Besides, the membrane exhibited excellent anti-oil-fouling properties. The flux recovery rate of PES/PAA (70.0%) far exceeds that of PES (37.9%) after three filtration and cleaning cycles. The membrane we developed is very valuable in oily wastewater treatment .
研究领域:
材料科学
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环境工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF MEMBRANE SCIENCE
·
2023
·
IF 9.5
Guangming Yan,Haoran Lu,Shushan Yuan,Xiao Deng,Junyong Zhu,Gang Zhang
In this study, a new category of copolymer was designed by side grafting of tertiary amines (TA) on polyaryl ether sulfone. The synthesized copolymers PES/ATA displayed superior thermal properties with a glass transition temperature of 200–225 °C. These copolymers with favorable film-forming properties were used to fabricate ultrafiltration membranes via a phase inversion approach. Surprisingly, it was found that the filtration performance of these resultant membranes could be reversibly tuned between a facile acid oxidation (CH 3 COOH:H 2 SO 4 :H 2 O 2 = 40:1:1) and alkali solution (solution of 20 wt% NaOH, immersed for 4–8 h) treatment. While the water flux of dye solution had a twofold reduction, the oxidized membranes showed distinctly enhancement of methylene blue rejection from 35% to 91.5% after oxidation treatment. Subsequently, alkali treatment of the oxidized membranes allowed their water flux to recover up to 89% as that of pristine membranes, and the methylene blue rejection can recover to almost the same as that of pristine membranes. This phenomenon was closely related to the introduced reactive TA units: the TA group in the polymeric membrane was converted into stimulus-responsive amine oxide (AO) unit, then its charge can be reversibly changed between the acid oxidation and alkali treatment, and that can be used to tune the electrostatic repulsion and further tuned the membrane pore size. In addition, compared with the polyarylene sulfone membrane, the mechanical properties of these membrane had almost no deterioration after several treatment cycle. This study supplies a novel and facile routine to fabricate functional membranes with reversible-tunable filtration properties.
研究领域:
材料科学
·
膜分离技术
✓ 已验证
产品关联
DOI
高影响因子
Catalysts
·
2023
·Vol. 13
·期 10
·1320
·
IF 3.9
Yinshan Xie,Xinning Wang,Hulin Li,Tao Wang,Wei Feng,Jian Li
Membrane separation has been widely utilized to eliminate pollutants from wastewater. Among them, a polyacrylonitrile (PAN) ultrafiltration (UF) membrane has presented outstanding stability, and distinguished chemical and thermal properties. However, UF membranes inevitably incur fouling issues during their operation procedure caused by contaminant adhesion on the membrane surface, which would restrict the operational efficiency and increase the maintenance cost. The conventional physical and chemical cleaning is not an effective technique to reduce the fouling due to the additional chemical addition and inevitable structure damage. Recently, UF membranes combined with photocatalytic materials are suggested to be a useful approach to conquer the membrane fouling issues. Herein, TiO2nanoparticles were utilized to blend with a PAN casting solution for fabricating a composite UF membrane via a phase inversion method. With a certain TiO2addition, the obtained membranes presented an enhancement of hydrophilicity, which could promote the water permeability and antifouling performance. The optimized M3 membrane prepared with 15.0 wt% PAN and 0.6 wt% TiO2exhibited an excellent water permeability up to 207.0 L m−2h−1bar−1with an outstanding 99.0% BSA rejection and superior antifouling property. In addition, the photocatalytic TiO2nanoparticles endowed the M3 membrane with a remarkable self-cleaning ability under the UV irradiation. This facile construction method offered new insight to enhance the UF membrane separation performance with an enhanced antifouling ability.Keywords:polyacrylonitrile;ultrafiltration;membrane fouling;TiO2;photocatalysis
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 PROTEOME RESEARCH
·
2023
·
IF 4.4
Ping Lu,Mengyuan Shan,Xuemeng Ji,Fuqi Deng,Yan Wang
High-performance liquid tandem mass spectrometry (HPLC-MS) is widely employed for protein analysis in biological systems. However, conventional proteomic sample pretreatment methods suffer from multiple steps and poor reproducibility. In this study, we introduce EPURISp (Enzymatic Digestion with Ultrafiltration and Rapid In-situ Sample Purification), a novel proteomic pretreatment technique that combines enzymatic digestion, ultrafiltration, and one-step temperature-controlled vacuum drying for efficient desalting. The EPURISp method exhibits excellent protein recovery rates across a wide range of molecular weights and hydrophilicity, surpassing traditional C18 desalting approaches. Practical proteomic analysis (PXD044209) utilizing EPURISp demonstrates the highest protein identification yield with remarkable reproducibility, which is particularly advantageous in membrane protein identification. Notably, EPURISp exhibits superior performance in minimizing oxidation and deamidation modifications compared with conventional FASP methods. This innovative EPURISp method represents a significant advancement in proteomics analysis, providing reliable and efficient results for mass spectrometry.
研究领域:
生物化学
·
蛋白质组学
·
分析化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Journal of Environmental Chemical Engineering
·
2023
·
IF 7.7
Xiaoxiang Cheng,Yinuo Liu,Xinsheng Luo,Xuewu Zhu,Jingtao Xu,Xinyu Zhang,Daoji Wu,Feiyong Chen,Heng Liang
The construction of replaceable dynamic membranes (DMs) on membrane surfaces is a promising strategy to effectively mitigate membrane fouling . Nevertheless, the efficiency of DMs in mitigating membrane fouling remains low due to the lack of microstructural configurations. Herein, we report a natural sepiolite (SEP) DM with a three-dimensional (3D) network structure for mitigating PES ultrafiltration (UF) membrane fouling. The abundant oxygen-containing groups on the surface of SEP nanofibers endowed SEP DM with good organic adsorption capacity, hindering the migration of contaminants such as humic acid (HA) and bovine serum albumin (BSA). Owing to the porous 3D network structure, SEP DM prevented the formation of a dense filter cake layer, which effectively mitigated the sharp rise in membrane resistance when filtering ideal HA and BSA solutions. For the actual secondary wastewater, SEP DM improved the removal of UV 254 and DOC by 29.8% and 22.5%, respectively, over the pristine PES membrane. The decrease in membrane-specific flux was mitigated by about 20%. Notably, the dynamic nature of SEP DM allowed the contaminated DM layer to be replaced by hydraulic cleaning, resulting in 99% flux recovery (only 89% for the pristine PES membrane). These findings are beneficial in providing new ideas for the mitigation and control of UF membranes.
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
·
2018
·
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
·
水处理工程
✓ 已验证
DOI
高影响因子
Desalination and Water Treatment
·
2024
·
IF 1
Chong Shen,Bin Peng,Qin Meng
Sulfobetaine methacrylate (SBMA) is a well-known zwitterionic molecule that can improve the hydrophilic property of hydrophobic membranes such as polysulfone (PSU). However, SBMA is too hydrophilic to dissolve in organic solvents. Hence, it is difficult to modify the polymer membranes via blending with their casting solution. This paper aims to synthesize an amphiphilic block polymers of polystyrene-block-sulfobetaine methacrylate (PS-b-SBMA) which can be well dissolved in organic solvents for membrane casting. The two PS-b-SBMA copolymers with SBMA content >28% were applied as the additives to cast the PSU ultrafiltration membrane. The PS-b-SBMA copolymer modified membranes showed lower contact angles and 3-folds higher water flux recovery after BSA treatment than the parent PSU membrane. Moreover, SEM images showed that the BSA contaminant on the modified membrane surfaces was much less than that on PSU membrane. Thus, such modified membranes can be applied to prevent protein fouling in the process of ultrafiltration.
研究领域:
高分子材料
·
膜科学与技术
·
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）