CHEMICAL ENGINEERING JOURNAL
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2024
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IF 13.3
Mingchun Bi,Yuning Liang,Weimeng Chi,Hongya Liu,Ying Chen
Nano zero-valent iron (nZVI) is extensively employed in the realm of wastewater treatment. However, conventional synthesis methods involve inherent risks of nZVI oxidation and aggregation, resulting in challenging recovery and potential waste generation. To address these concerns and improve stability, nano zero-valent nickel (nZVNi) was employed as a modifier for nZVI. The modified nZVNi/nZVI was successfully blended with polydopamine (PDA)-modified polyvinylidene fluoride (PVDF) powder, enabling the preparation of a novel hydrophilic composite membrane termed nZVNi/nZVI-PDA@PVDF (NFPP). PDA played a crucial role in effectively immobilizing nZVI particles and preventing their oxidation and aggregation. Scanning electron microscopy was used to confirm the consistent dispersion of nZVNi/nZVI particles both on the surface of the membrane and within its pores. Moreover, the NFPP membrane exhibited excellent performance in removing Cr(VI), with a maximum adsorption capacity of 75.65 mg/g. The presence of PDA endowed the NFPP membrane with a plentiful supply of hydroxyl and amino groups, enhancing its hydrophilicity, antioxidation properties, and loading capacity for nZVNi/nZVI. Additionally, the NFPP membrane demonstrated remarkable resistance to interference under different pH and ionic conditions. The removal of Cr(VI) by the NFPP membrane followed a pseudo-second-order kinetics and Langmuir isotherm adsorption model. Furthermore, the NFPP membrane retained good performance and stability in Cr(VI) removal even after undergoing five cycles. This study indicates that the highly efficient NFPP composite material holds promising potential for application as a functional material in heavy metal wastewater treatment.
研究领域:
环境科学
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材料科学
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产品关联
DOI
高影响因子
Journal of Water Process Engineering
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2024
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IF 6.3
Zhaohui Zhang,Wenshuo Hu,Cong Ma,Tong Zhang,Liang Wang
Understanding the irreversible fouling mitigation performance of conductive membranes is crucial for engineering applications. In this study, the effectiveness of conductive membranes in mitigating the irreversible fouling caused by typical membrane pollutants and actual surface water was investigated. The results indicated that the conductive membranes had the greatest mitigating effect on irreversible fouling caused by humic substances and the weakest mitigating effect on that caused by proteins. The growth rates of irreversible membrane fouling over five-cycle filtration with conductive membranes were reduced by 58.6 % (humic acid), 42.3 % (sodium alginate), and 30 % (bovine serum albumin) compared to those without power. Moreover, conductive membranes exhibited a commendable irreversible fouling mitigation effect when treating real surface water. The irreversible fouling growth rate and resistance decreased by 41.6 % and 49.9 %, respectively, compared to those without power. Although the increase in the ionic strength of the feed water weakened the effectiveness of the conductive membranes in irreversible fouling mitigation, it was still significantly better than that without power.
研究领域:
环境科学
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材料科学
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产品关联
DOI
高影响因子
ACS Applied Polymer Materials
·
2024
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IF 4.4
Yulan Tang,Dongrui Zhou,Xiankun Zhang,Xianyuan Sun,Zesheng Sheng,Ting Li
Laccase–Cu3BTC2 was synthesized from laccase and Cu3BTC2 metal–organic skeleton materials and doped with the highly hydrophilic amphiphilic polymer polyvinylidene fluoride-graft-poly(ethylene glycol) methyl ether methacrylate (PVDF-g-PEGMA) as a bimodifier in the casting solution using in situ synthesis to prepare high-flux poly(vinylidene fluoride) (PVDF) membranes. Due to the high hydrophilicity of PVDF-g-PEGMA and laccase–Cu3BTC2, the PVDF-modified membranes were more hydrophilic; the water contact angle decreased from 93.45° to 79.46°. It exhibited optimal performance when its mass fraction relative to PVDF was 8.0%. Pure water flux and the sodium alginate retention rate reached 1975.61 L/(m2·h) and 87.79%, respectively, and the flux recovery and reversible and irreversible contamination ratio were 84.64%, 71.07%, and 15.36%, respectively, substantially enhancing the pollution resistance of the PVDF membrane.
研究领域:
材料科学
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环境工程
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生物技术
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
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2020
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IF 10.652
Na Li,Huai-duo Chen,Yong-ze Lu,Ming-chao Zhu,Zhao-xia Hu,Shou-wen Chen,Raymond Jianxiong Zeng
In recent years, nanoscale zero-valent iron (nZVI) has been considered an appealing alternative for halogenated organic compound removal for its advantages, such as its high activity. However, easy aggregation limits nZVI activity. In this study, functional nZVI-modified PVDF membranes (nZVI@PVDF membranes) were successfully prepared by a simple and easy-to-follow filter-press coating method and was applied in the ultrafiltration process to treat 2-chlorophenol (2-cp) wastewater. Scanning electron microscopy showed that nZVI particles were relatively uniformly distributed on the membrane surface and formed a fluffy and porous space-stacked structure. 2-cp ultrafiltration degradation results illustrated that nZVI@PVDF membranes revealed good 2-cp removal efficiencies ranged from 56.06% to74.62%. These 2-cp removal efficiencies were higher than those for Fe supported on powder materials and were relatively comparable to those for nZVI composite membranes prepared by complex methods (e.g., blend spinning and cross-linking methods). Furthermore, the 2-cp degradation efficiencies by nZVI@PVDF membranes were not affected much in the presence of natural organic matter and different ions, demonstrating a robust anti-interference ability of nZVI@PVDF membrane. The mechanism underlying its robust performance likely resulted from that nZVI was uniformly distributed and loaded layer by layer on the PVDF membrane surface with high loading capacity, which guaranteed high nZVI activity, layer-layer interception of pollutants and complete reaction between nZVI and pollutants. These findings provide key insights into how nZVI@PVDF membranes could be integrated into the treatment of wastewater containing refractory pollutants.
研究领域:
环境科学
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材料科学
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产品关联
DOI
高影响因子
JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY A-CHEMISTRY
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2018
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IF 2.891
Bo Gao,Weiping Chen,Jiadong Liu,Jiajun An,Lei Wang,Ying Zhu,Mika Sillanpää
Based on the concept of dynamic membrane and photocatalytic membrane reactor (PMR), the dynamic photocatalytic membrane reactor is developed via deposition of ZnIn 2 S 4 suspension on polyvinylidene fluoride (PVDF) membrane. Operating with effluent circulating to the photocatalytic membrane reactor, the highest total organic carbon (TOC) removal efficiency of 57% is obtained after 3 h reaction with 1.88 mg cm −2 photocatalyst under the flux of 84.06 L m −2 h −1 and light intensity of 50 mW cm −2 . Operating with continuous influent and effluent mode under the flux of 26.09 L m −2 h −1 and light intensity of 50 mW cm −2 , an average of 50% removal efficiency can be maintained during the 24 h photocatalytic reaction with photocatalyst loading of 1.88 mg cm −2 when the initial concentration of tetracycline is 10 mg L −1 . Under the same operating conditions, more than 92% removal efficiency can be maintained during 36 h photocatalytic reaction when lower initial concentration of 100 μg L −1 is applied. After this reaction, the characterizations show that the surface and structure of PVDF basement membrane are not affected.
研究领域:
环境科学
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化学工程
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产品关联
DOI
高影响因子
DESALINATION
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2015
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IF 3.756
Lei Wang,Danxi Huang,Xudong Wang,Xiaorong Meng,Yongtao Lv,Xin Wang,Rui Miao
To obtain a high-performance polyvinylidene fluoride (PVDF) membrane, low-temperature thermally induced phase separation (LT-TIPS) was employed to prepare microporous flat PVDF membranes and hollow-fiber membranes using diluent mixtures of triethylphosphate and diethylene glycol monoethyl ether acetate. The membrane morphology was characterized by scanning electron microscopy (SEM) and atomic force microscopy (AFM). The results show that thermally induced phase separation (TIPS) played a more important role than nonsolvent-induced phase separation (NIPS) in determining the cross-sectional morphology of the membranes, and the surface structure was mainly affected by NIPS in a low-temperature (0 °C) coagulation bath . By increasing the temperature of the coagulation bath, different structures of membranes, such as spherulites and cellular and sponge structures, were observed. It is believed that the formation mechanism of these membranes depended on a combined NIPS and TIPS process. Wide-angle X-ray diffraction (XRD) analysis indicated that PVDF crystallized into an α-phase crystal structure for all the membranes tested. In addition, the porosity, tensile strength and filtration performance of the flat membranes were measured. On the basis of the above results, a hollow fiber membrane with highly interconnected pores and high porosity could be prepared employing LT-TIPS.
研究领域:
材料科学
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化学工程
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产品关联
DOI
高影响因子
ACS Applied Materials & Interfaces
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2022
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IF 10.383
Zhu Xiong,Yongshi Huang,Zehui Huang,Yiwen Shi,Fangshu Qu,Gaosheng Zhang,Jingxin Yang,Shuaifei Zhao
Membrane surface fouling is often reversible as it can be mitigated by enhancing the crossflow shear force. However, membrane internal fouling is often irreversible and thus more challenging. In this study, we developed a new superhydrophilic poly(vinylidene fluoride) (P-PVDF) membrane confined with nano-Fe3O4 in the top skin layer via reverse filtration to reduce internal fouling. The surface of the P-PVDF membrane confined with nano-Fe3O4 had superwetting properties (water contact angle reaching 0° within 1 s), increased roughness (from 182 to 239 nm), and enhanced water affinity. The Fe3O4@P-PVDF membrane surface showed a thicker and enhanced hydration layer, which prevented foulants from approaching membrane surfaces and pores, thereby improving the rejection. For example, when 50 ppm humic acid (HA) solution was used as the feed, the removal efficiency of the Fe3O4@P-PVDF membrane was ∼67%, while the HA removal of the P-PVDF membrane was only ∼20%. The results from the resistance-in-series model showed that nanoconfinement of Fe3O4 in the top skin layer of the membrane allowed foulants to accumulate on the membrane surface (i.e., surface fouling) rather than within the internal pores (i.e., internal fouling). The filtration results under crossflow fouling and cleaning confirmed that the Fe3O4@P-PVDF membrane had higher surface fouling but it was much more reversible and much lower internal fouling compared with the control membrane. Our fouling analysis offers new insights into mass transfer mechanisms of the membrane with a nanoconfinement-enhanced hydration layer. This study provides an effective strategy to develop membranes with low internal fouling propensities.
研究领域:
环境科学
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材料科学
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产品关联
DOI
PubMed
高影响因子
JOURNAL OF MEMBRANE SCIENCE
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2023
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IF 9.5
Li Chen,Rui Cui,Weiguo Pan,Jiangdong Dai,Minjia Meng,Xiaohui Dai,Jianming Pan
Efficient separation of single rare earth element such as neodymium (Nd) has become an important research topic due to the supply crisis which seriously restricts the application and promotion of rare earth permanent magnets. PVDF-based separation membranes prepared by non-solvent induced phase separation (NIPS) method usually exhibited hydrophobic surface properties resulting in performance attenuation and operation cost increase. This article applied an easily available NADES from betaine and lactic acid to regulate and control the coagulation bath of a polymer inclusion membrane (PIM) for the separation of Nd, Sm and Dy ions. Evidences for the formation of DES were characterized via 1 H NMR and FT-IR, and betaine showed more obvious changes than lactic acid during the formation of DES via hydrogen bonds . With the help of DES, pores on the surface were much larger and richer, and the migration of P O and P–O groups to the lower epidermal layer of the membrane made the surface layer become more hydrophilic. DES accelerated the liquid-liquid demixing process and led to faster membrane-forming speed and typical finger-like macrovoids and short vertical penetration channels, which could be observed at high DES contents, and a DES content of 5 wt% was found the most optimal considering the overall permeability and separation performances. As an effective means to improve membrane's performances, adding hydrophilic NADESs at a proper ratio in the coagulation bath would be conducive to form more porous structures, higher surface hydrophilicity, optimized permeability and separation performances.
研究领域:
材料科学
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环境工程
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化学工程
✓ 已验证
DOI
高影响因子
Arabian Journal of Chemistry
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2023
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IF 6
Yingjian Zhai,Jing Yang
There is an urgent need for an antifouling membrane to treat the large volume of dye-containing wastewater generated annually by the dyeing and printing industry. PDA@ZnO/PVDF membranes were synthesized by doping polydopamine (PDA) and zinc oxide (ZnO) nanoparticles into the polyvinylidene fluoride (PVDF) membranes via non-solvent induced phase separation (NIPS) method in which polyvinylpyrrolidone (PVP) and lithium chloride (LiCl) were chosen as the porogens respectively. Their microstructures were characterized, and the membranes were examined for antifouling properties and membrane separation performance. The presence of PDA@ZnO nanoparticles on the PVDF membrane was evidenced by X-ray diffraction (XRD), scanning electron microscopy (SEM) and Fourier transform infrared (FTIR) measurements. The addition of PDA@ZnO enhanced the mechanical strength and hydrophilicity of the nanocomposite membranes. The PVDF membranes' water permeability and antifouling properties improved following mixing modification, according to the dye filtration test. The pure water flux of PDA@ZnO/PVDF hybrid membranes changed from 260.0 L·m −2 ·h −1 ·bar −1 to 1339.2 L·m −2 ·h −1 ·bar −1 by varying the concentration of PDA@ZnO nanoparticles from 0 wt% to 1.6 wt%. The retention performance of the modified membranes was shown to be significantly superior to the pure PVDF membrane. The modified membranes with the addition of 2.0 wt% PVP and 1.6 wt% PDA@ZnO nanoparticles had highly disperse blue 79 (DB 79) retentions (88.5%), indicating that the modified membrane possessed the characteristics of a promising membrane for the purification of dye. Tests found that PDA@ZnO significantly improved the membrane's antifouling performance.
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
Journal of Materiomics
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2020
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IF 5.797
Gajula Prasad,Jun-Wei Liang,Wei Zhao,Yingbang Yao,Tao Tao,Bo Liang,Sheng-Guo Lu
The effect of a N,N-dimethylformamide (DMF)/acetone solvent system (3:7, 4:6, 5:5, 6:4, 7:3) and spinning medium (air and water) on the membrane morphology and the structure-property relationship were investigated. A facile method was optimized to generate a porous, polymer-fiber membrane via the combinative effect of electrospinning and thermally inducing phase separation of the DMF/acetone (4:6) solvent system in a water medium. The attenuated total reflection (ATR) - Fourier transform infrared (FTIR) results showed an increased β-phase compared to the pristine poly(vinylidene fluoride) (PVDF). The XRD and DSC results further confirmed that the co-existing α- and β-phases in the pristine PVDF were converted into a unique β-phase in the electrospun membranes. In addition, the solvent uptake percentage of the DMF/acetone (4:6) solvent system in a water medium (540) is much greater than that in an air medium (320), and over two times better than that of commercial polyethylene (PE) membranes (190). Similarly, the discharge capacity of the PVDF membrane separator prepared with the DMF/acetone (4:6) solvent system in a water medium is higher than that of the air medium. This enhancement of solvent uptake might be due to the interconnected porous morphology present in the water medium.
研究领域:
材料科学
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化学工程
✓ 已验证
DOI
高影响因子
Membranes
·
2024
·Vol. 14
·期 11
·241
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IF 3.3
Wenbin Sun,Longbo Xia,Ping Luo,Dong Zou
Polyvinylidene fluoride (PVDF) membranes are extensively utilized in membrane distillation (MD) for water treatment. However, traditional methods easily form asymmetrical membranes with dense skin layers that are detrimental to membrane flux. Herein, an eco-friendly PVDF membrane was fabricated by utilizing a delayed phase separation process without using any pore-forming agents. In addition, methyl-5-(dimethylamino)-2-methyl-5-oxopentanoate (PolarClean) was used as a green solvent without posing risks to humans and the environment. It was demonstrated that the PVDF concentration is crucial in influencing the microstructures and performance of the resulting membranes. As the PVDF concentration increased, the morphology changed significantly, resulting in a reduction of pore size. When feeding the device with NaCl solution at a concentration of 35 g/L, the MD water vapor flux reached 18.49 kg·m −2 ·h −1 , while maintaining a salt rejection of over 99.97% during the continuous operation for 24 h. This work presented a method for producing green PVDF membranes via delayed phase inversion with satisfactory water vapor flux and salt rejection, highlighting their prospect for effective applications in MD for water 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
PROCESS SAFETY AND ENVIRONMENTAL PROTECTION
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2024
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IF 6.9
Chengyu Yang,Xiaoju Yan,Cong Ma,Xinping Lin,ChengZhi Yao,XueYan Li
Organic membrane fouling is a major obstacle to the application of membrane distillation in low surface tension wastewater treatment. Membrane modification might be an effective way to mitigate membrane fouling. This study mainly explored the mechanism of enhanced anti-fouling performance of the MXene modified PVDF membrane by applying XDLVO theory combined with surface elemental integration (SEI) method. The rough membrane surfaces were first reconstructed using fractal function. Then, the interaction energy between low surface tension substances and the membranes before and after modification was calculated. The results showed that oil droplets and surfactant fouling were mainly caused by hydrophobic attraction due to Lewis acid-base (AB) interaction energy. By modifying the virgin PVDF membrane with MXene nanoparticles, the polar component of membrane surface tension (γ AB ) increased significantly, so that the interaction energy between all contaminants and membrane surface changed from attraction to repulsion. In addition, roughness weakened the interaction energy between contaminants and membrane surface but significantly lengthened the range of interaction distance, which together determined the ability of the membrane to attract or repel the contaminants. These findings may improve the understanding of the structure-effect relationship between membrane modification and anti-fouling ability, and provide new insights into the membrane modification for MD.
研究领域:
环境科学
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材料科学
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产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）