PROCESS SAFETY AND ENVIRONMENTAL PROTECTION
·
2024
·
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
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
Petroleum Science
·
2024
·
IF 6
Wei-Feng Yuan,Yu-Long Yang,Lu Yuan,Ji-Rui Hou
Fine particle detachment and subsequent migration can lead to severe pore plugging and consequent permeability decline. Therefore, it is crucial to quantify the critical condition when fine particle detachment occurs. The frequently observed deviations or even contradictions between experimental results and theoretical predictions of fines detachment arise from an insufficient understanding of adhesion force that can be highly influenced by salinity and temperature. To clarify the intrinsic influence of salinity and temperature on fines detachment, adhesion forces between carboxyl microspheres and hydrophilic silica substrates in an aqueous medium were measured at various salinities and temperatures using atomic force microscopy (AFM). The AFM-measured adhesion force decreases with increasing salinity or temperature. Trends of mean measured adhesion forces with temperature and salinity were compared with the DLVO and XDLVO theories. DLVO theory captured the trend with temperature via the impact of temperature on electric double layer interactions, whereas XDLVO theory captured the observed trend with salinity via the impact of salinity on the repulsive hydration force. Our results highlight the significance of hydration force in accurately predicting the fate of fines in porous media.
研究领域:
石油工程
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表面科学
·
胶体化学
✓ 已验证
DOI
高影响因子
SCIENCE OF THE TOTAL ENVIRONMENT
·
2023
·
IF 9.8
Yunhai Zhang,Zihao Chen,Yuexiao Shi,Qing Ma,Haoran Mao,Ying Li,Hao Wang,Yongjun Zhang
The co-occurrence of microplastics (MPs) and organic contaminants in aquatic environment can complexify their environmental fate via sorption interactions, especially when the properties of MPs can even vary due to the aging effect. Thus, quantitatively clarifying the sorption mechanisms is required to understand their environmental impacts. This study selected popularly occurring carbamazepine (CBZ) and four types of MPs as model systems, including polyethylene, polyvinyl chloride , polyethylene terephthalate and polystyrene in their pristine and aged forms, to investigate the sorption isotherms, kinetics, and desorption. The variation of MPs during the aging process were analyzed with scanning electron microscopy, contact angle, Fourier transform infrared spectroscopy , and X-ray photoelectron spectroscopy. It was found that the aging process elevated the sorption capacity and intensified the desorption hysteresis of CBZ on MPs via increasing the surface roughness , decreasing the particle size, and altering the surficial chemistry of all MPs. The extended Derjaguin–Landau–Verwey–Overbeek (XDLVO) theory was innovatively applied hereby to calculate the interfacial free energies and revealed that the hydrophobic interaction was significantly lessened after aging for all MPs with the slightly enhanced van der Waals interaction. Then the total interfacial free energies were dropped down for all MPs, which resulted in their declined specific sorption capacity. This work reveals the sorption mechanisms of CBZ on pristine and aged MPs with XDLVO and provides a useful reference to study the sorption of other neutral organics onto MPs.
研究领域:
环境科学
·
生态学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2025
·
IF 9
Wei Zhang,Weicheng Fu,Zihao Wang,Shuang Wu,Zhipeng Wang,Yaoming Wang
In this study, organic solutions (30–120 mg/L HA, BSA or SA) and composite solutions (5.93–10.15 wt% inorganic salts with 75 mg/L HA, BSA or SA) were used to investigate the membrane fouling behavior in the vacuum membrane distillation (VMD) system. The different permeate flux attenuation and fouled membrane morphology implied distinct membrane fouling mechanisms during VMD process. Furthermore, we employed the extended Derjaguin-Landau-Verwey-Overbeek (XDLVO) theory as an effective approach to analyze membrane fouling mechanisms. The results showed that the total interaction energy was negative (attraction) within the separation distance of 1–2 nm by applying the XDLVO approach, indicating that a pristine membrane was more prone to fouling. Finally, we elucidated distinct membrane fouling mechanisms in the VMD system. The inorganic feed solution readily induced inorganic fouling on the membrane surface and pore wetting, while organic feed solution and combined feed solution did not cause membrane wetting, conversely, only organic fouling and combined fouling were identified on the membrane surface. This study was expected to facilitate understanding of membrane fouling mechanisms in the VMD process.
研究领域:
环境科学
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化学工程
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材料科学
✓ 已验证
DOI
高影响因子
JOURNAL OF COLLOID AND INTERFACE SCIENCE
·
2023
·
IF 9.9
Xiujia You,Liguo Shen,Ying Zhao,Die Ling Zhao,Jiaheng Teng,Hongjun Lin,Renjie Li,Yanchao Xu,Meijia Zhang
To gain a thorough understanding of interfacial behaviors such as adhesion and flocculation controlling membrane fouling, it is necessary to simulate the actual membrane surface morphology and quantify interfacial interactions. In this work, a new method integrating the rough membrane morphology reconstruction technology (atomic force microscopy (AFM) combining with triangulation technique), the surface element integration (SEI) method, the extended Derjaguin-Landau-Verwey-Overbeek (XDLVO) theory, the compound Simpson's approach, and the computer programming was proposed. This new method can exactly mimic the real membrane surface in terms of roughness and shape, breaking the limitation of previous fractal theory and Gaussian method where the simulated membrane surface is only statistically similar to the real rough surface, thus achieving a precise description of the interfacial interactions between sludge foulants and the real membrane surface. This method was then applied to assess the antifouling propensity of a polyvinylidene fluoride (PVDF) membrane modified with Ni-ZnO particles (NZPs). The simulated results showed that the interfacial interactions between sludge foulants in a membrane bioreactor (MBR) and the modified PVDF-NZPs membrane transformed from an attractive force to a repulsive force. The phenomenon confirmed the significant antifouling propensity of the PVDF-NZPs membrane, which is highly consistent with the experimental findings and the interfacial interactions described in previous literature, suggesting the high feasibility and reliability of the proposed method. Meanwhile, the original programming code of the quantification was also developed, which further facilitates the widespread use of this method and enhances the value of this work.
研究领域:
环境科学
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材料科学
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表面化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ACS Applied Materials & Interfaces
·
2014
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IF 5.9
Yunhai Zhang,Guicai Liu,Shuili Yu,Jun Zhang,Yulin Tang,Pan Li,Yifei Ren
Surface functionalization of multiwalled carbon nanotubes (MWCNTs) was performed using mixed acid and ethylenediamine. The materials were characterized by electron microscope, X-ray diffraction, Raman spectra, Fourier transform infrared, N2 adsorption–desorption, and X-ray photoelectron spectroscopy. The pH-dependent sorption of tetrabromobisphenol A (TBBPA) onto raw and functionalized MWCNTs was investigated. A decrease in TBBPA uptake was found to be dependent on the adsorptive pKa in alkaline conditions. Two types of MWCNTs exhibited rapid binding kinetics for TBBPA sorption within 20 min. The kinetics of TBBPA sorption onto MWCNTs were analyzed using a pseudo-second-order model, an intraparticle diffusion model and Boyd model. The results showed that TBBPA sorption on MWCNTs and N-MWCNTs could be well described by the pseudo-second-order model, and the external diffusion (boundary layer diffusion) was the rate-limiting step. The extended Derjaguin–Landau–Verwey–Overbeek (XDLVO) theory was applied to calculate interfacial free energies and to explain the sorption characteristics between the sorbent and solute. This analysis revealed that hydrophobic attractive interactions (i.e., interfacial AB interactions) were dominant in TBBPA sorption onto MWCNTs.
研究领域:
环境科学
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材料科学
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化学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Water Quality Research Journal
·
2023
·Vol. 58
·期 3
·215-229
·
IF 2.3
Wu Yuyang
View large Download slide View large Download slide Close modal Perfluorinated compounds (PFCs) are significant pollutants known for their high toxicity and resistance to natural degradation, posing a severe threat to both the global environment and human health. In this study, a polyamide (PA) membrane with an intermediate layer structure of MXene-TiO 2 (referred to as MXT-NFM) was utilized for the removal of PFCs. Experimental results confirm that MXT-NFM exhibited remarkable capacity in intercepting PFCs, accompanied by the high water flux. To gain insights into the mechanisms governing membrane fouling induced by PFCs, inorganic ions, and organics, a series of fouling tests were conducted using MXT-NFM under diverse conditions. Additionally, the XDLVO theory was employed to provide a theoretical perspective on the interactions occurring during the fouling process. The findings suggest that the MXene-TiO 2 intermediate layer contributed to the exceptional hydrophilicity and rough surface properties, enabling multiple functionalities. These include alleviating membrane pore plugging, improving the physical configuration of the PA layer, and effectively mitigating fouling phenomena in coexisting systems during practical applications. Moreover, the particle size of pollutant colloids and the acid–base interaction were identified as decisive factors influencing the development of membrane fouling. Perfluorinated compounds (PFCs) were efficiently removed by MXene-TiO 2 interlayered nanofiltration membrane. Influences of various parameters on the PFCs removal were investigated. Influences of various conditions on the membrane fouling were studied. Mechanism of membrane fouling was analyzed by the XDLVO theory.
研究领域:
环境科学
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膜分离技术
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材料科学
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水处理工程
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物理化学
✓ 已验证
DOI
高影响因子
JOURNAL OF HAZARDOUS MATERIALS
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2021
·
IF 10.588
Tianjiao Xia,Shunli Li,Hanwei Wang,Chenming Guo,Chen Liu,Anning Liu,Xuetao Guo,Lingyan Zhu
The transport behaviors of nanomaterials , in especial multifunctional nanohybrids have not been well disclosed until now. In this study, environmentally relevant conditions, including cation types, ionic strength and pH, were selected to investigate the transport and retention of graphene oxide-hematite (GO-Fe 2 O 3 ) nanohybrids and a photoaged product in saturated sandy columns. Results show that more hybridization of hematite led to decreased negative surface charge, while increased particle size and hydrophobicity of the nanohybrids, which depressed their transport according to extented Derjaguin-Landau-Verwey-Overbeek (XDLVO) theory. However, the inhibitory transport of photoaged nanohybrids was attributed to their distinct surface roughness caused by relatively high hybridization and photoirradiation. Notably the restrained transport was alleviated in the CaCl 2 saturated media, since the less surface O-functional groups of the corresponding nanohybrids reduced the cation bridging effect caused by Ca 2+ . Similarly, increasing pH promoted the transport of the nanohybrids in NaCl saturated media, particularly for the nanohybrids that contained rich O-functional groups, but exerted inconspicuous effect on mobility of the nanohybrids in CaCl 2 saturated media. These observations highlight that both XDLVO interactions and surface roughness may work together to impact the transport and fate of the burgeoning, versatile nanohybrids in the environment.
研究领域:
环境科学
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纳米科技
✓ 已验证
产品关联
DOI
PubMed
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2024
·
IF 8.1
Yunxuan Chen,Jun Nan,Mingqi Guo,Yibo Zhang,Jinghui Wang,Qi Wang,Rui Fang
Finding alternative solutions of water source containing short-term relative high turbidity and large organic content is a pressing need in view of the inherent limitations of traditional inorganic coagulants. Requirement of significant dosage increase for conventional iron and aluminum salt coagulants can create several challenges including dose adjustment, suboptimal performance and high concentration of residual metal ions. In this study, acrylamide monomer (AM) and methacryloyloxyethyltrimethylammonium chloride (DMC) were grafted onto starch and carboxymethyl starch to obtain novel cationic and amphoteric starch-modified coagulants. Concurrently, the obtained coagulants were comprehensively evaluated under varying simulated water quality conditions to analyze their turbidity and organic matter removal efficiencies. Polymerized aluminium chloride (PACl) was used as the reference coagulant to evaluate the roles of polymer charge density, total charge, and molecular chain length in the coagulation mechanism for further illustration of their efficacy. In comparison to the traditional coagulant PACl, the modified coagulant was found to be more effective in enhancing flocculation and aggregation behavior, lowering of energy barriers, and enhancing adsorption energy by using the Density Functional Theory (DFT) calculations and Extended Derjaguin-Landau-Verwey-Overbeek (XDLVO) theory based investigation of the mechanism. Moreover, these behaviors were mainly attributed to significant exchange of charge density between coagulant and the pollutants. Additionally, in order to facilitate accurate and efficient treatment of water having diverse qualities, quadratic polynomial equation based mathematical model was constructed for quantitative analysis and model prediction. Findings of this study point towards an effective and precise approach to coagulation technology and thereby enabling sustainable and efficient purification of turbid source water containing large organic matter.
研究领域:
环境科学
·
水处理工程
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
Journal of Environmental Chemical Engineering
·
2023
·
IF 7.7
Chaoxu Zhou,Jin Wang,Qingyun Zhang,Mengmeng Dou,Kaili Huo,Chao Han,Boru Gao
Nanocomposite membranes (NCMs) incorporated with nanomaterials have recently received increasing attention, but the preparation of high-performance membranes is still challenging due to the hydrophilicity and self-aggregation of the nanoparticles . In this study, graphite carbon nitride containing nitrogen defects was modified using dopamine (PDA@DCN) for effective alleviation of the agglomeration of nanoparticles resulting in a uniform casting solution. A non-solvent-induced phase separation method was adapted to prepare PVDF NCMs by using PDA@DCN as an effective additive. Superior permeability and selectivity were exhibited by the PDA 0.25 @DCN/PVDF 2 membrane (where a DA concentration of 0.25 g/100 mL was used in PDA@DCN preparation and 2% PVP was added during the membrane preparation) with the pure water flux of 390 L/(m 2 ·h) and Bovine serum albumin (BSA) rejection of 95.9%. The extended Derjaguin-Landau-Verwey-Overbeek (XDLVO) theory revealed that the improvement of the flux recovery rate of PDA 0.25 @DCN/PVDF 2 was due to the decreased attractive interaction for fouling. Ternary phase diagram and viscosity experiments confirmed that the addition of PDA 0.25 @DCN accelerated phase inversion rate (as evident from thermodynamics and kinetics) and increased the porosity with smaller average surface pore size, which is expected to have good permeability and selectivity as an ultrafiltration membrane. Moreover, an excellent self-cleaning performance was demonstrated by PDA 0.25 @DCN/PVDF 2 , with a flux recovery rate of 84.5%, simply under visible light irradiation, which indicates its potential for environment-friendly practical application.
研究领域:
材料科学
·
环境工程
·
化学工程
·
膜技术
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF MEMBRANE SCIENCE
·
2021
·
IF 8.742
Tong Zhang,Jie Zhang,Qiaoying Wang,Hao Zhang,Zhiwei Wang,Zhichao Wu
A novel vermiculite nanoparticles (Verm NPs) modified poly(vinylidene fluoride) (PVDF) ultrafiltration membrane was firstly fabricated via surface coating at pH 7.2–7.3. The dense but porous modified surface formed by controlling the self-polymerization rate of dopamine at relatively weak alkalinity provided both high water flux and rejection rate of BSA, which broke the trade-off between permeability and rejection rate. The contact angle of optimal modified membrane decreased from 69.6° to 45.0°, showing the effectively enhancement of hydrophilicity. By filtrating two kinds of real oil-in-water emulsions, the stable flux of modified membrane was approximately 2 times higher than that of pristine membrane for both low and high concentration oil-in-water emulsions. In addition, the Verm-PVDF membrane also showed a higher removal efficiency of oil and total organic carbon . According to membrane fouling model analysis, the fouling behavior including adsorption, deposition, blockage of membrane pores and formation of cake layer had obviously alleviated after Verm modification for the two kinds of oil-in-water emulsions due to the formation of water layer by isomorphism substitution and surface hydroxylation of Verm NPs. Assessed by extended Derjaguin-Landau-Verwey-Overbeek (XDLVO) theory, Verm-PVDF membrane exhibited a higher energy barrier and an extremely strong repulsive force for foulants to overcome in low and high concentration emulsions during fouling. Overall, the improved antifouling ability and separation performance of modified membrane indicated that the inartificial Verm NPs was a robust material for pH-control membrane modification with potential application value in oil/water separation.
研究领域:
材料科学
·
环境工程
·
化学工程
·
纳米技术
✓ 已验证
DOI
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2021
·
IF 7.312
Minli Hu,Qidong Wu,Chen Chen,Songmiao Liang,Yuanhui Liu,Yuhua Bai,Alberto Tiraferri,Baicang Liu
Complex organic matter causes severe fouling when membranes are applied for shale gas wastewater (SGW) treatment. This study reports the grafting of a zwitterionic polymer brush consisting of poly (sulfobetaine methacrylate) (PSBMA) onto the surface of a commercial nanofiltration (NF) membrane via electron transfer-atom transfer radical polymerization (ARGET-ATRP) to achieve anti-fouling property, especially against organic foulants. Compared to the pristine NF membranes, the PSBMA-grafted NF membrane showed high performance when challenged by SGW as a feed stream: (1) The flux stability was significantly improved during long-term operation, with a 64.28% increase in flux normalization at 50% recovery rate of SGW, while maintaining a suitable initial flux and near constant ion removal rate; (2) Based on excitation-emission-matrix spectra integrated in the fluorescence region, the removal of protein-like organic matters and humus-like organic matters increased by 34% and 16.5%, respectively; (3) The XDLVO theory supports the hypothesis that the hydrophobic interactions between the membrane surface and organic foulants were reduced by enhancing the Lewis acid-base interaction energy. The proposed anti-fouling zwitterionic membranes has potential in industrial application for the on-site reuse of SGW.
研究领域:
环境科学
·
膜技术
·
水处理
✓ 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）