Environmental Science-Nano
·
2024
·
IF 5.8
Mengxia Wang,Meng Zhang,Qi Han,Yufei Shu,Xun Liu,Beizhao Chen,Yuchao Chen,Bei Liu,Zhongying Wang
Mercury (Hg) contamination in groundwater poses significant environmental and health risks, necessitating effective remediation strategies. Recently, molybdenum disulfide (MoS2) nanosheets have emerged as a promising nanomaterial for the remediation of Hg-associated contaminated groundwater. However, the complex interactions between ubiquitous natural organic matter (NOM) and MoS2 may play a significant role in controlling the removal of Hg from groundwater. In this study, we investigated the mechanisms underlying the role of NOM in Hg(II) removal by MoS2. Our findings demonstrated that NOM inhibited the Hg(II) removal by MoS2 from groundwater at a high molar ratio of Hg/MoS2. However, at a low molar ratio of Hg/MoS2, NOM hardly affected the removal performance of MoS2 on Hg(II) because NOM was unable to compete with sufficient MoS2 to complex with Hg(II). The inhibitory effect of NOM on Hg(II) removal was found to be determined by both the molecular weight (MW) and functional groups of NOM: the NOM fraction with higher MW exhibited a higher degree of inhibition, and the –SH groups displayed preferential binding of Hg(II) rather than the –COOH group. It was concluded that the reduction of MoS2 to Hg(II) gradually decreased with increasing addition of NOM, attributed to NOM complexation with Hg(II). Overall, this study provides insights into the significance of NOM characteristics in controlling the removal of Hg(II) from groundwater.
研究领域:
环境科学
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纳米技术
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水处理
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产品关联
DOI
高影响因子
JOURNAL OF HAZARDOUS MATERIALS
·
2024
·
IF 12.2
Yuxi Zhang,Yamin Deng,Jiangkai Xue,Yihan Cheng,Yulun Nie,Kunfu Pi,Yao Du,Xianjun Xie,Jianbo Shi,Yanxin Wang
The environmental fate of arsenic (As) relies substantially on its speciation, which occurs frequently coupled to the redox transformation of manganese. While trivalent manganese (Mn(III)), which is known for its high reactivity, is believed to play a role in As mobilization by iron (oxyhydr)oxides in dynamic aquifers, the exact roles and underlying mechanisms are still poorly understood. Using increasingly complex batch experiments that mimick As-affected aquifer conditions in combination with time-resolved characterization, we demonstrate that Mn(III)-NOM complexes play a crucial role in the manganese-mediated immobilization of As(III) by ferrihydrite and goethite . Under anaerobic condition , Mn(III)-fulvic acid (FA) rapidly oxidized 31.8% of aqueous As(III) and bound both As(III) and As(V). Furthermore, Mn(III)-FA exerted significantly different effects on the adsorption of As by ferrihydrite and goethite. Mn(III)-FA increased the adsorption of As by 6–16% due to the higher affinity of oxidation-produced As(V) for ferrihydrite under circumneutral conditions. In contrast, As adsorption by crystalline goethite was eventually inhibited due to the competitive effect of Mn(III)-FA. To summarize, our results reveal that Mn(III)-NOM complexes play dual roles in As retention by iron oxides , depending on the their crystallization. This highlights the importance of Mn(III) for the fate of As particularly in redox fluctuating groundwater environments.
研究领域:
环境科学
·
地球化学
·
水文地质学
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DOI
PubMed
高影响因子
Membranes
·
2023
·Vol. 13
·期 4
·449
·
IF 4.2
Yuqi Sun,Runze Zhang,Chunyi Sun,Zhipeng Liu,Jian Zhang,Shuang Liang,Xia Wang
Mixtures of silica nanoparticles (SiO2NPs) and natural organic matter (NOM) are ubiquitous in natural aquatic environments and pose risks to organisms. Ultrafiltration (UF) membranes can effectively remove SiO2NP–NOM mixtures. However, the corresponding membrane fouling mechanisms, particularly under different solution conditions, have not yet been studied. In this work, the effect of solution chemistry on polyethersulfone (PES) UF membrane fouling caused by a SiO2NP–NOM mixture was investigated at different pH levels, ionic strengths, and calcium concentrations. The corresponding membrane fouling mechanisms, i.e., Lifshitz–van der Waals (LW), electrostatic (EL), and acid–base (AB) interactions, were quantitatively evaluated using the extended Derjaguin–Landau–Verwey–Overbeek (xDLVO) theory. It was found that the extent of membrane fouling increased with decreasing pH, increasing ionic strength, and increasing calcium concentration. The attractive AB interaction between the clean/fouled membrane and foulant was the major fouling mechanism in both the initial adhesion and later cohesion stages, while the attractive LW and repulsive EL interactions were less important. The change of fouling potential with solution chemistry was negatively correlated with the calculated interaction energy, indicating that the UF membrane fouling behavior under different solution conditions can be effectively explained and predicted using the xDLVO theory.Keywords:ultrafiltration;membrane fouling;silica nanoparticles (SiO2NPs);natural organic matter (NOM);interfacial interaction;xDLVO theory
研究领域:
环境科学
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膜技术
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水处理
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产品关联
DOI
PubMed
高影响因子
ENVIRONMENTAL SCIENCE & TECHNOLOGY
·
2015
·
IF 5.33
Yongguang Yin,Mohai Shen,Zhiqiang Tan,Sujuan Yu,Jingfu Liu,Guibin Jiang
Ubiquitous natural organic matter (NOM) plays an important role in the aggregation state of engineered silver nanoparticles (AgNPs) in aquatic environment, which determines the transport, transformation, and toxicity of AgNPs. As various capping agents are used as coatings for nanoparticles and NOM are natural polymer mixture with wide molecular weight (MW) distribution, probing the particle coating-dependent interaction of MW fractionated natural organic matter (Mf-NOM) with various coatings is helpful for understanding the differential aggregation and transport behavior of engineered AgNPs as well as other metal nanoparticles. In this study, we investigated the role of pristine and Mf-NOM on the aggregation of AgNPs with Bare, citrate, and PVP coating (Bare-, Cit-, and PVP-AgNP) in mono- and divalent electrolyte solutions. We observed that the enhanced aggregation or dispersion of AgNPs in NOM solution highly depends on the coating of AgNPs. Pristine NOM inhibited the aggregation of Bare-AgNPs but enhanced the aggregation of PVP-AgNPs. In addition, Mf-NOM fractions have distinguishing roles on the aggregation and dispersion of AgNPs, which also highly depend on the AgNPs coating as well as the MW of Mf-NOM. Higher MW Mf-NOM (>100 kDa and 30–100 kDa) enhanced the aggregation of PVP-AgNPs in mono- and divalent electrolyte solutions, whereas lower MW Mf-NOM (10–30 kDa, 3–10 kDa and <3 kDa) inhibited the aggregation of PVP-AgNPs. However, all the Mf-NOM fractions inhibited the aggregation of Bare-AgNPs. For PVP- and Bare-AgNPs, the stability of AgNPs in electrolyte solution was significantly correlated to the MW of Mf-NOM. But for Cit-AgNPs, pristine NOM and Mf-NOM has minor influence on the stability of AgNPs. These findings about significantly different roles of Mf-NOM on aggregation of engineered AgNPs with various coating are important for better understanding of the transport and subsequent transformation of AgNPs in aquatic environment.
研究领域:
环境科学
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纳米技术
·
化学
✓ 已验证
DOI
PubMed
高影响因子
Journal of Environmental Chemical Engineering
·
2025
·
IF 7.2
Yimu Qiao,Xue Han,Yijia Ren,Feiyong Chen,Cuizhen Sun,Jin Wang,Zhigang Yang,Linxu Xu,Xue Shen,Rupeng Liu
The extensive use of ibuprofen (IBU) and acetaminophen (APAP) has led to their accumulation in surface water, resulting in combined pollution with natural organic matter (NOM). In this study, a novel modified chitosan-based coagulant (CTS-DMDAAC) was successfully synthesized by adding ceric ammonium nitrate (CAN) to make chitosan (CTS) and dimethyldiallylammonium chloride (DMDAAC) produce free radicals for graft copolymerization. The study investigated the effects of pH, initial NOM concentration, and suspended particulates on the performance of contaminant removal and the characteristics of flocs. Through analysis of the Zeta potential and floc characteristics, the primary flocculation mechanisms were identified as: net capture and sweep, charge neutralization, and bridging effect. CTS-DMDAAC demonstrated effective removal of NOM, particularly humus, but encountered challenges in removing small-molecule pharmaceuticals such as IBU and APAP, with removal rates below 15%. To enhance the removal rate of small organic molecules, powdered activated carbon (PAC) was incorporated into the coagulation system, resulting in increased removal rates of IBU and APAP to 71.44% and 79.9%, respectively. Additionally, PAC improved the bridging capacity during coagulation, resulting in a 1.25-fold increase in the strength factor and a 2.34-fold increase in the recovery factor of the flocs. These findings suggest that the combined use of PAC and CTS-DMDAAC presents a novel approach for treating water bodies contaminated with NOM and pharmaceutical complexes.
研究领域:
环境科学
·
水处理工程
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产品关联
DOI
高影响因子
CHEMOSPHERE
·
2016
·
IF 3.698
Huili Wang,Mei Wang,Hui Wang,Jiajia Gao,Randy A. Dahlgren,Qing Yu,Xuedong Wang
The compound 2,2′,4,4′,5,5′-hexabrominated diphenyl ether (BDE-153) is an intermediate photolytic product in the degradation of highly brominated diphenyl ethers to lower brominated forms. Herein, we report the effects of two natural organic matter (NOM) sources, Suwannee River fulvic acid (SRFA) and Pony Lake fulvic acid (PLFA), on BDE-153 photolysis in water. The rate constant ( k ) and half-life of BDE-153 was 2.26 × 10 −2 min −1 and 30.72 min under UV–Vis irradiation (direct photolysis at λ > 290 nm). The k value for BDE-153 decreased markedly in the presence of NOM with a larger decrease in the presence of PLFA than SRFA. Electron spin resonance (ESR) demonstrated generation of free radicals in the photolytic process that mainly involved 1 O 2 and OH. The biomolecular k values for reaction of 1 O 2 and OH with BDE-153 were 3.65 × 10 6 and 7.70 × 10 8 M −1 s −1 , respectively. The contribution of OH (28.7–31.0%) to the indirect photolysis of BDE-153 was higher than for 1 O 2 (12.9–14.9%). The photolytic rate of BDE-153 in oxygen-rich (aerated) solution was much slower than in oxygen-poor (nitrogen-sparged) conditions, demonstrating that 3 NOM* is a more effective reagent for degradation of BDE-153 than 1 O 2 . Addition of sorbic acid (a 3 NOM* quencher) significantly reduced the photolytic rate of BDE-153 confirming the important role of 3 NOM* in indirect photolysis. In the presence of NOM, BDE-153 indirect photolysis was facilitated mainly by reaction with 3 NOM* and OH. To the best of our knowledge, this is the first comprehensive investigation of indirect photolysis of BDE-153 in water containing NOM.
研究领域:
环境科学
·
化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Journal of Water Process Engineering
·
2015
·
IF 0
Xiangrong Chen,Jianquan Luo,Benkun Qi,Weifeng Cao,Yinhua Wan
Polyethylene oxide (PEO)-modified ultrafiltration (UF) membranes were prepared using polyacrylonitrile-graft-polyethylene oxide (PAN-g-PEO) copolymers through immersion precipitation phase inversion method. Compared to PAN membrane, the PEO-modified UF membranes possessed extraordinary hydrophilic surface owing to the enrichment of PEO segments, which was confirmed by X-ray photoelectronic spectroscopy (XPS). The effects of membrane hydrophilicity on the organic fouling resistance were investigated by means of the resistance-in-series model. The results showed that the hydrophilic modification of UF membrane contributed to the fouling control in bovine serum albumin (BSA) and Escherichia coli ( E . coli ) bacteria filtration. The antifouling ability of the membranes increased with increasing PEO content. The pure water flux could recover completely after filtering BSA and bacteria, respectively, for the membranes with 25.2% and 8.5% PEO content. In contract, the increase of membrane hydrophilicity had a negative effect on the humic acid (HA) and sodium alginate (SA) filtration. The membrane permeability of the PAN membrane unexpectedly increased after HA or SA filtration, while the flux recovery ratio of PEO-modified membranes decreased with increasing PEO content. The differences in fouling behavior of the various organic foulants on hydrophobic or hydrophilic membrane were attributed to the nature of organic foulants and their interaction with membranes.
研究领域:
环境科学
·
生物技术
✓ 已验证
DOI
ELECTROCHIMICA ACTA
·
2025
·
IF 5.6
Linpiao Cheng,Shuyue Liu,Yinan Liu,Xiangyi Tang,Mue Tang,Xinhua Xu,Xiaoshu Lv
Electrocatalytic hydrodechlorination (EHDC) represents a sustainable approach to detoxifying the chlorinated organic pollutants (COPs). However, electrodes often suffer from fouling due to the ubiquitous natural organic matters (NOM) in surface water bodies. Herein we demonstrated that pre-mixing humic acid (HA) with palladium nanoparticles (Pd NPs) is an ingenious approach to address this issue. The introduction of HA improved dispersion of Pd NPs, enhanced surface hydrophilicity to promote H* generation, and increased electrostatic repulsion and steric-hinerance against NOM in solution. As a result, the as-synthesized HA 0.2 -Pd electrode exhibits significantly improved EHDC performance and anti-NOM poisoning ability. In the batch experiment, the HA 0.2 -Pd NPs achieved removal efficiencies of 91.3 and 80.8 % respectively, for treating 50.0 mg L −1 of 2,4-dichlorophenol (2,4-DCP, a probe COP) from contaminated water in the absence or presence of 20 mg L −1 HA (representative of NOM) at -0.85 V vs . Ag/AgCl. Compared to that, the pure Pd/C electrode experienced a marked efficacy decline from 82.9 to 56.5 % in the presence of HA. Moreover, the HA 0.2 -Pd/C electrode maintained a steady efficiency above 92.0 % over 12 h EHDC in a continuous-flow cell, while only 60.0 % for the Pd/C electrode. When subjected to contaminated natural water, the HA 0.2 -Pd/C electrode afforded an EHDC efficiency of 75.4 %, significantly surpassing the 39.4 % efficiency of Pd/C electrode.
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 RESEARCH
·
2022
·
IF 13.4
Zhaoyu Bai,Shanshan Gao,Huarong Yu,Xiwen Liu,Jiayu Tian
Catalytic membrane can achieve sieving separation and advanced oxidation simultaneously, which can improve the effluent water quality while reducing membrane fouling. In this study, the catalytic membranes (M 2+ Al@AM) were fabricated by loading different binary layered metal oxides (M 2+ Al-LMO: MnAl-LMO, CuAl-LMO and CoAl-LMO) on alumina ceramic substrate membranes (AM) via vacuum filtration followed by calcination process. The performance of the catalytic membranes was investigated by filtering actual surface water. It was found that the presence of peroxymonosulfate (PMS) could mitigate membrane fouling effectively, as evidenced by the increase of normalized flux from 0.28 to 0.62 in CoAl@AM/PMS system, from 0.25 to 0.52 in CuAl@AM/PMS system, and from 0.22 to 0.31 in MnAl@AM/PMS system, respectively. Correspondingly, the CoAl@AM exhibited the highest removal for UV 254 , TOC and fluorescent components in the surface water, followed by CuAl@AM and MnAl@AM. Quenching effect of phenol and furfuryl alcohol proposed the surface-bound radicals and singlet oxygen were the major reactive oxygen species in the M 2+ Al@AM/PMS systems. Interface free energy calculations confirmed the in-situ PMS activation could enhance the repulsive interactions between NOM and the membranes, thus mitigating membrane fouling. This work provides an original but simple strategy for catalytic ceramic membrane preparation and new insights into the mechanism of membrane fouling mitigation in catalytic membrane system.
研究领域:
环境工程
·
水处理技术
·
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2025
·
IF 13.2
Kexin Kang,Situ Mu,Jianrui Niu,Yongkun Shi,Jing Zhang,Chun Liu,Junjun Ma
Natural brackish water bodies constitute complex mixtures. Accordingly, the production of high-quality drinking water from such sources necessitates the concurrent removal of salts and natural organic matter (NOM). A dual-anode circuit system (DA-FCDI) was developed by integrating electrochemical oxidation with flow-electrode capacitive deionization (FCDI). This dual-circuit configuration enables modulation of both desalination and electrochemical oxidation performances, while simultaneously regulating the charge and energy distribution between these two processes. At the same time, it was found that an increase in voltage difference between the internal and external circuits is beneficial for the degradation of organic matter. Furthermore, I − /I 3 − redox electrolytes were employed to expand the voltage window, thereby overcoming the voltage threshold limitation of the DA-FCDI system and enhancing its overall performance. When the applied voltage is 1.2 V - 1.8 V, ASRR and ATRR are 0.059 μmol cm −2 min −1 and 0.34 μg cm −2 min −1 , respectively, and the specific energy consumption is only 0.052 kWh/m 3 .Compared to other technologies, this FCDI and electrochemical oxidation integrated device significantly reduces the consumption of chemical agents and simplifies the process flow. More importantly, while improving economic efficiency, it endows the system with high adaptability and controllability to different water qualities. This study breaks through the bottleneck of traditional single technology that cannot regulate and remove salt and organic matter separately.
研究领域:
环境工程
·
水处理技术
·
电化学工程
·
脱盐技术
·
污染物去除
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF NANOPARTICLE RESEARCH
·
2022
·Vol. 24
·期 9
·1-16
·
IF 2.533
Zhang Xiaoran,Du Xinyue,Wang Mingxiu,Li Zhifei,Zhang Ziyang,Tan Chaohong,Liu Junfeng,Li Haiyan
SiO 2 -engineered nanoparticles (SiO 2 -ENPs) are one of the most commonly employed nanomaterials. There was a lack of research on the comprehensive effects of environmental factors on the stability of SiO 2 -ENPs. In the present work, the aggregation size, surface charge, and percentage of nanoparticles have been studied under the presence of monovalent/divalent cations combined with natural organic matter (NOM), in an effort to provide a comprehensive investigation of the stability of SiO 2 -ENPs in complex environmental conditions. Results show that NOM adsorbed to the particles and made their zeta potential more negative, hence stabilizing them by electrostatic repulsion, and the stability of nano-SiO 2 in NOM solutions follows the order of pH 9 > pH 7 > pH 5. In addition, SiO 2 -ENPs size in solutions with humic acid (HA) was larger than that with fulvic acid (FA). The aggregation of SiO 2 -ENPs enhanced with the increase of cation concentrations, and divalent cations (Ca 2+ ) show stronger influence on SiO 2 -ENPs aggregate than monovalent cations. Divalent cations partially neutralized the adsorbed organic matter, and aggregation was enhanced with Ca 2+ , suggesting the presence of specific Ca 2+ -NOM bridges. The aggregation of SiO 2 -ENPs in electrolyte (CaCl 2 or NaCl) and CaCl 2 + NOM solutions follows in the order of pH 5~pH 9 > pH 7, showing that weakly acidic or alkaline conditions are not favorable for the stability of SiO 2 -ENPs in complex environmental systems.
研究领域:
环境科学
·
纳米技术
✓ 已验证
产品关联
DOI
高影响因子
WATER RESEARCH
·
2020
·
IF 9.13
Hankun Yang,Wu Xue,Mengjie Liu,Kai Yu,Wenzheng Yu
Oxidation is a widely used method in drinking water treatment to mitigate the membrane fouling caused by the natural organic matters (NOM) from the surface water during ultra-filtration (UF) and nano-filtration (NF) processes, and H 2 O 2 is one of the common oxidants for it. However, the oxidation capability of H 2 O 2 at neutral pH is lower, compared to the acidic and alkaline conditions. In order to improve the efficiency of NOM oxidation at neutral pH, a carbon-doped Fe 3 O 4 peroxidase-like nanozyme (CFPN) was synthesized in this study and used as a high-performance catalyst for H 2 O 2 to generate hydroxyl radical . The oxygen-containing groups on the carbon structure of CFPN can form an acidic microenvironment, allowing H 2 O 2 to produce hydroxyl radical by catalysis in neutral conditions. The results of hydrophilicity analysis, zeta potential , high-performance liquid size exclusion chromatography (HPSEC), Fourier transform infrared spectrum (FTIR) and flux indicated that the hydroxyl radical can oxidize the hydrophobic matters of humic acid (HA) into hydrophilic matters by Fenton reaction or electrophilic addition reaction, which can mitigate the fouling of NF membranes. The results of the same test for the bovine serum albumin (BSA) indicated that the hydroxyl radical can mitigate the fouling of UF membranes by degrading the tertiary and secondary structures of BSA and partly oxidizing the side chain groups. In addition, two types of surface water samples were used to verify the above mechanism, and the results indicated that the hydroxyl radical treatment at neutral pH is a new viable and effective strategy to significantly mitigate the NOM fouling of UF and NF membranes.
研究领域:
环境科学
·
材料科学
·
水处理工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）