JOURNAL OF SEPARATION SCIENCE
·
2016
·Vol. 39
·期 11
·2146-2155
·
IF 2.741
Xiuzhi Bai,Ting Zhang,Haipu Li,Zhaoguang Yang
Chloroanisoles, particularly 2,4,6-trichloroanisole, are commonly identified as major taste and odor compounds in water. In the present study, a simple and efficient method was established for the simultaneous determination of chloroanisoles and the precursor 2,4,6-trichlorophenol in water by using low-density-solvent-based simultaneous dispersive liquid–liquid microextraction and derivatization followed by gas chromatography with electron capture detection. 2,4-Dichloroanisole, 2,6-dichloroanisole, 2,4,6-trichloroanisole, 2,3,4-trichloroanisole, and 2,3,6-trichloroanisole were the chloroanisoles evaluated. Several important parameters of the extraction-derivatization procedures, including the types and volumes of extraction solvent and disperser solvent, concentrations of derivatization agent and base, salt addition, extraction-derivatization time, and temperature were optimized. Under the optimized conditions (80 μL of isooctane as extraction solvent, 500 μL of methanol as disperser solvent, 60 μL of acetic anhydride as derivatization agent, 0.75% of Na 2 CO 3 addition w/v, extraction-derivatization temperature of 25°C, without salt addition), a good linearity of the calibration curve was observed by the square of correlation coefficients ( R 2 ) ranging from 0.9936 to 0.9992. Repeatability and reproducibility of the method were < 4.5% and <7.3%, respectively. Recovery rates ranged from 85.2 to 101.4%, and limits of detection ranged from 3.0 to 8.7 ng/L. The proposed method was applied successfully for the determination of chloroanisoles and 2,4,6-trichlorophenol in water samples.
研究领域:
分析化学
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环境科学
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产品关联
DOI
PubMed
高影响因子
ELECTROCHIMICA ACTA
·
2013
·
IF 3.777
Zhiqiao He,Keji Lin,Junjun Sun,Lina Wen,Chao Gao,Jianmeng Chen,Shuang Song,Yanyun Qian,Weiping Liu
A kinetic model for the electrochemical dechlorination of polychlorinated biphenyls (PCBs) will be an important contribution to the design and optimization of a continuous reactor. Initially, the electrocatalytic hydrodechlorination of 2-chlorobiphenyl (2-ClBP) to biphenyl at a palladium-modified nickel foam (Pd/Ni) cathode in a batch reactor was used as a model reaction for a quantitative study of the influences of the operating parameters, including temperature, the initial concentrations of PCBs, current density and the amount of Pd loading, on the apparent reaction rate. The dechlorination was found to follow pseudo first-order kinetics with respect to the 2-ClBP concentration. It was also found that a simple global power law rate equation , with Arrhenius dependency, can be used to describe the correlation between the pseudo first-order reaction rate constants and the reaction conditions. Subsequently, a mathematical model for predicting the performance of reductive dechlorination of 2-ClBP on Pd/Ni electrodes in a continuous stirred tank reactor was constructed, based on the batch-reaction kinetics. The suitability of the model was validated by performing experiments in and out of the range of reaction conditions applied in the batch reactor. The results show that the calculated values are a good fit to the experimental data.
研究领域:
环境科学
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电化学工程
✓ 已验证
产品关联
DOI
高影响因子
ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
·
2014
·Vol. 21
·期 7
·5201-5210
·
IF 2.757
Chen Xi,Yao Xiaoyan,Yu Chunna,Su Xiaomei,Shen Chaofeng,Chen Chen,Huang Ronglang,Xu Xinhua
Soil pollution by polychlorinated biphenyls (PCBs) arising from the crude disposal and recycling of electronic and electrical waste (e-waste) is a serious issue, and effective remediation technologies are urgently needed. Nanoscale zerovalent iron (nZVI) and bimetallic systems have been shown to promote successfully the destruction of halogenated organic compounds. In the present study, nZVI and Pd/Fe bimetallic nanoparticles synthesized by chemical deposition were used to remove 2,2′,4,4′,5,5′-hexachlorobiphenyl from deionized water, and then applied to PCBs contaminated soil collected from an e-waste recycling area. The results indicated that the hydrodechlorination of 2,2′,4,4′,5,5′-hexachlorobiphenyl by nZVI and Pd/Fe bimetallic nanoparticles followed pseudo-first-order kinetics and Pd loading was beneficial to the hydrodechlorination process. It was also found that the removal efficiencies of PCBs from soil achieved using Pd/Fe bimetallic nanoparticles were higher than that achieved using nZVI and that PCBs degradation might be affected by the soil properties. Finally, the potential challenges of nZVI application to in situ remediation were explored.
研究领域:
环境科学
·
化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
SCIENCE OF THE TOTAL ENVIRONMENT
·
2017
·
IF 4.9
Jirui Yang,Feng Shen,Mo Qiu,Xinhua Qi
This paper reports a nonreductive dechlorination pathway (dehydrochlorination) of lindane in the presence of N -MWCNTs (CNT-N1 and CNT N2) under environmentally relevant conditions. The enhanced catalytic dehydrochlorination at mild pH values (7.0–9.0) was mainly attributed to the Lewis base nature of nitrogen functional groups on the surface of N -MWCNTs, based on FT-IR spectra, X-ray photoelectron spectroscopy and CO 2 -TPD profile. Amine and pyridinic nitrogen species were inferred as the main basic sites that were responsible for the dehydrochlorination of lindane. The concentration of lindane was unchanged in homogenous alkaline aqueous solutions at pH 7.0 and 8.0 within 6 d, and up to 89.5% of lindane remained at pH 9.0. In sharp contrast, the reaction rate constant ( k obs ) increased from 0.024 to 0.876 d − 1 with the increasing pH from 7.0 to 9.0 when CNT-N2 catalyst was used. All lindane was transformed in the presence of CNT-N2 at pH 9.0, leading to a much greater k obs as compared to that obtained in homogenous solution (0.876 vs 0.019 d − 1 ). Even at neutral pH condition, the k obs obtained in the presence of CNT-N2 was higher than that observed in weakly alkaline solution (0.024 d − 1 at pH 7.0 vs 0.019 d − 1 at pH 9.0). γ-1,3,4,5,6-pentachlorocyclohexene and trichlorobenzene isomers were detected as the intermediate and final products, respectively. It might be inferred that amine and pyridinic nitrogen species could attack the hydrogen atom attached to the β‑carbon, and the dehydrochlorination of lindane followed a β-elimination mechanism. This study provides an alternative dechlorination way for making lindane less toxic and better biodegradable under mild conditions, which is beneficial for complete mineralization of lindane when coupled with microbial degradation.
研究领域:
环境科学
·
化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2025
·
IF 9
Haoyu Yan,Peng Wang,Pu Huang,Cheng Shen,Jian Sun,Tao Song
Ammonia (NH 3 ) is widely recognized as a carbon-free hydrogen carrier with high energy density, making it a promising energy vector for sustainable energy systems. However, its efficient storage and release remain technical challenges. In this study, the low-temperature NH 3 adsorption-desorption performance of four pure metal chlorides (CaCl 2 , MgCl 2 , MnCl 2 , and CuCl 2 ) was systematically evaluated. Among them, CuCl 2 and MnCl 2 exhibited superior NH 3 uptake capacities, but also suffered from volume expansion and particle agglomeration during repeated cycling. To overcome these limitations, composite sorbent pellets were developed by supporting metal chlorides on Al 2 O 3 via a graphite-casting method. The resulting CuCl 2 -based composite pellet achieved an optimized balance of high NH 3 adsorption capacity (∼ 0.36 g NH 3 /g), excellent regeneration efficiency (> 96 %), and adequate mechanical strength. Excessive CuCl 2 loading reduced both regeneration efficiency and mechanical stability, while lower loading enhanced active phase dispersion and sorbent performance. 30 wt% CuCl 2 offered the best performance in terms of adsorption, regeneration, and structural durability. Additionally, the optimized Cu 30 -Al-C sorbent maintained stable NH 3 adsorption capacity over 20 cycles, confirming excellent reusability. The enhanced performance was attributed to the synergistic effects of Al 2 O 3 support and the hydrophobic nature of the graphite-casting process, which enabled uniform distribution of active compound and mitigated structural deterioration during cycling. These results demonstrate the feasibility of graphite-casted, Al 2 O 3 -supported metal chlorides as structurally stable and regenerable NH 3 sorbents for low-temperature ammonia storage applications.
研究领域:
储能
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材料科学
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化学工程
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可持续能源
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吸附技术
✓ 已验证
产品关联
DOI
高影响因子
ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
·
2016
·Vol. 23
·期 19
·19266-19280
·
IF 2.76
Yang Hui,Hu Yuanan,Cheng Hefa
Sorption of 2-chlorophenol (2-CP), 2,4-dichlorophenol (2,4-DCP), and 2,4,6-trichlorophenol (2,4,6-TCP) on a range of dealuminated zeolites were investigated to understand the mechanism of their sorption on microporous minerals, while the influence of common metal cations, solution pH, and humic acid was also studied. Sorption of chlorophenols was found to increase with the hydrophobicity of the sorbates and that of the microporous minerals, indicating the important role of hydrophobic interactions, while sorption was also stronger in the micropores of narrower sizes because of greater enhancement of the dispersion interactions. The presence of metal cations could enhance chlorophenol sorption due to the additional electrostatic attraction between metal cations exchanged into the mineral micropores and the chlorophenolates, and this effect was apparent on the mineral sorbent with a high density of surface cations (2.62 sites/nm 2 ) in its micropores. Under circum-neutral or acidic conditions, neutral chlorophenol molecules adsorbed into the hydrophobic micropores through displacing the “loosely bound” water molecules, while their sorption was negligible under moderately alkaline conditions due to electrostatic repulsion between the negatively charged zeolite framework and anionic chlorophenolates. The influence of humic acid on sorption of chlorophenols on dealuminated Y zeolites suggests that its molecules did not block the micropores but created a secondary sorption sites by forming a “coating layer” on the external surface of the zeolites. These mechanistic insights could help better understand the interactions of ionizable chlorophenols and metal cations in mineral micropores and guide the selection and design of reusable microporous mineral sorbents for sorptive removal of chlorophenols from aqueous stream.
研究领域:
环境科学
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化学工程
·
水处理
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Journal of Magnesium and Alloys
·
2020
·
IF 7.115
Shaolong Li,Yusi Che,Chenyao Li,Yongchun Shu,Jilin He,Bin Yang,Jianxun Song
The electrochemical behavior of Mg 2+ and Al 3+ in LiCl-KCl (mass 4: 1) melt at 973 K was studied on a Mo electrode systematically by cyclic voltammetry, square wave voltammetry and chronopotentiometry. The results showed that the reductions of Mg 2+ and Al 3+ were reversible processes controlled by the rate of the mass transfer. When Mg 2+ and Al 3+ coexisted in LiCl-KCl melt, they had no significant effect on the reduction potential of each other. The equilibrium potentials of Mg 2+ /Mg and Al 3+ /Al were obtained by open circuit potential method. Their apparent standard potentials were also calculated in this system and the values were −2.52 V vs Cl 2 /Cl − , −1.66 V vs Cl 2 /Cl − , respectively. Correspondingly, the apparent Gibbs free energies of Mg 2+ /Mg and Al 3+ /Al were −485.71 kJ/mol, −480.78 kJ/mol. Finally, potentiostatic electrolysis was performed on a Mo electrode in LiCl-KCl-MgCl 2 -AlCl 3 (the mass ratio of MgCl 2 to AlCl 3 was 10:1) melt at different potentials. The components of the deposits were characterized by scanning electron microscope and energy dispersive spectroscopy. The study revealed that the content of Al in the deposit decreased as the overpotential increased and Al tended to segregate at the grain boundaries.
研究领域:
材料科学
·
电化学
✓ 已验证
DOI
高影响因子
SCIENCE OF THE TOTAL ENVIRONMENT
·
2021
·
IF 7.963
Kejin Zhou,Sheng Ye,Qi Yu,Jingji Chen,Pang Yong,Xiaoyan Ma,Qingsong Li,Andrea M. Dietrich
Dissolved nitrogenous organic matter in water can contain precursors of disinfection by-products (DBPs), especially nitrogenous DBPs (N-DBPs). Amino acids are ubiquitous as dissolved nitrogenous organic matter in source water and can pass through drinking water treatment processes to react with disinfectants in finished water and in the distribution system. Phenylalanine (Phe) was selected as a model amino acid precursor to investigate its derived DBPs and their variations during a chlorination regime that simulated water distribution with residue chlorine. The 7-day DBPs formation potential (DBPsFP) test with chlorine revealed chlorination by-products of phenylalanine including trihalomethanes (THMs), haloacetic acids (HAAs), haloacetonitriles (HANs), and halonitromethanes (HNMs), but not trichloronitromethane (TCNM) which was a significant N-DBP detected during the first 48 h of chlorine contact. The formation of most carbonaceous DBPs (C-DBPs) increased with chlorination time; however N-DBPs and non-chlorinated byproducts of phenylacetonitrile and phenylacetaldehyde reached their highest concentration after 2 h of reaction, and then gradually decreased until below detection after 7 days. The chlorination influencing factors indicated that light enhanced the peak yield of DBPs; the pH value showed different influences associated with corresponding DBPs; and the presence of bromide ions (Br − ) generated a variety of bromine-containing DBPs. The DBPsFP test with chloramine reduced C-DBPs generation to about 1/3 of the level observed for chlorine disinfection and caused an increase in dichloroacetonitrile. Surveillance of DBPs during drinking water distribution to consumers should consider the varying contact times with disinfectants to accurately profile the types and concentrations of C-DBPs and N-DBPs present in drinking water.
研究领域:
环境科学
·
公共卫生
✓ 已验证
DOI
高影响因子
RSC Advances
·
2014
·Vol. 4
·期 48
·25440-25446
·
IF 3.708
Yanlin Ren,Guangyin Fan,Weidong Jiang,Bin Xu,Fuan Liu
Magnetic palladium/reduced graphene oxide nanocomposites (Pd/rGO-Fe3O4) were prepared by depositing Pd nanoparticles on an rGO-Fe3O4 magnetic support. The as-prepared nanocomposites were investigated as catalysts for the hydrodechlorination of 4-chlorophenol in the aqueous phase. The complete conversion of 4-chlorophenol (with a concentration as high as 2.5 g L−1) to phenol was obtained in a reaction time of 40 min at room temperature and balloon hydrogen pressure without any additives. The excellent catalytic activity of the Pd/rGO-Fe3O4 can be attributed to the small particle size of Pd, and an electron-deficient state of Pd in the catalyst as a result of the strong interaction between the active sites and the oxygen of the oxygen-containing groups on the rGO-Fe3O4 support.
研究领域:
环境科学
·
催化化学
✓ 已验证
DOI
高影响因子
SCIENCE OF THE TOTAL ENVIRONMENT
·
2018
·
IF 4.61
Jianeng Xu,Conghui Huang,Xiaoyang Shi,Shengkun Dong,Baoling Yuan,Thanh H. Nguyen
PVC pipe loops were constructed to simulate household premise plumbing. These pipe loops were exposed to water treated by physical processes at three water treatment plants in Xiamen, China from August 2016 to June 2017. After the biofilms were allowed to develop inside the pipes, these pipes were deconstructed and exposed to organic-free chlorine solution buffered at pH 6.8 ± 0.2 for 48 h. The decay of chlorine by these biofilms was higher than by the effluent waters that were used to grow the biofilms. A chlorine consumption mass balance model elucidated the role of both the diffusion of chlorine into the biofilm and the reaction of chlorine with the biofilm matrix. Comparable concentrations of trihalomethanes were quantified from the reaction between chlorine and source water organic matters, and chlorine and the biofilm, further emphasizing the role of biofilms in the safety of disinfected drinking water. These findings imply that when chlorine is used in the drinking water distribution system, the ubiquitous presence of biofilms may cause the depletion of chlorine and the formation of non-negligible levels of toxic disinfection byproducts.
研究领域:
环境科学
·
公共卫生
·
水处理工程
✓ 已验证
DOI
PubMed
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2021
·
IF 7.312
Pengbo Zhao,Junquan Meng,Rui Zhang,Bing Cao,Pei Li
Pervaporation (PV) desalination membranes have good anti-fouling properties due to its hydrophilic dense surface structure. However, organic fouling is inevitable in long-term operation. Sodium hypochlorite (NaClO) is commonly used for cleaning organic pollutant, but it may damage polymeric membrane. Thus, designing membrane material with good chlorine resistance is crucial for expanding its lifespan. In this study, polyvinyl alcohol (PVA) was selected to prepare PV membrane in concern of its hydrophilicity and good film forming property. Its chlorine resistance was improved by removing the more active 1,2-diols of PVA by reacting with sodium periodate, grafting with poly (styrene-co-maleic anhydride) to decrease its crystallinity, and crosslinking using a fluorocarbon surfactant (FS). The resulting PV membrane exhibited the highest reported chlorine resistance of 768000 ppm·h among PV and RO membranes with a high-water flux of 44.5 ± 1.5 kg/m 2 ·h and salt rejection of 99.93%. A long-term fouling and cleaning cycle experiment was carried out using 10000 ppm humic acid to mimic organic foulants. The flux was recovered 100% after the NaClO cleaning. Hence, the chlorine-resistant PV membrane had the ability for sustainable desalination application.
研究领域:
高分子材料科学
·
膜分离技术
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环境工程
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水处理
·
化学工程
✓ 已验证
DOI
高影响因子
RESEARCH ON CHEMICAL INTERMEDIATES
·
2022
·Vol. 48
·期 10
·4105-4118
·
IF 3.134
Tang Wanjun,Liu Yunyi,Ding Shuang,Zhao Dongmei,Li Tingcheng,Xie Guangyong
MoV 2 O 8 micro-cuboids were environment-friendly prepared via a facile one-step solvothermal route followed by thermal treatment with vanadium pentoxide and ammonium molybdate as raw materials without using harmful solvents or surfactants. Characterization by XRD, FTIR, XPS, SEM and TEM showed that MoV 2 O 8 formed a layered structure by the stacking of nanosheets and assumed a micro-cuboid shape with a thickness of 150∓30 nm, a width of 350∓110 nm and a length of 680∓18 nm. For the first time, the catalytic properties of MoV 2 O 8 micro-cuboids were investigated for the gas-phase ammoxidation of p -chlorotoluene (PCT) to p -chlorobenzonitrile (PCBN). The as-prepared catalyst exhibited high activity and selectivity in the ammoxidation of PCT to PCBN, with a near 100% conversion and 83.6% yield.
Graphical abstract
研究领域:
材料化学
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催化化学
·
纳米材料
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绿色合成
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有机反应工程
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）