CHEMICAL ENGINEERING JOURNAL
·
2024
·
IF 13.3
Xuqing Zou,Yizhou Feng,Min Hu,Daohui Lin,Kun Yang,Wenhao Wu
Biochars was widely employed to immobilize chlorinated aliphatic hydrocarbons (CAHs) in groundwater. Biodegradation of adsorbed CAHs may be able to regenerate biochars, but was scarcely explored. In this study, therefore, biodegradation of trichloroethylene (TCE) adsorbed on a biochar prepared at 700 °C (WBC700) by Dehalococcoides mccartyi 195 ( Dhc 195) was investigated. Aqueous TCE was completely degraded to ethene by Dhc 195 within 28 days, while 87.5 % of WBC700-adsorbed TCE was degraded to ethene within 63 days. The slower biodegradation of WBC700-adsorbed TCE could be attributed to its lower accessibility to Dhc 195 caused by the steric effects of WBC700. The adsorption capacity of WBC700 for TCE remained 80.4 % after five adsorption-bioregeneration cycles, indicating that the microbial degradation could be a highly efficient method to regenerate biochars. The microbial degradation was mainly through the electron transfer from Dhc 195 to TCE mediated by biochars as electron conductor or shuttle, but was not assisted by desorption or extracellular redox active species. Compared with biodegradation of aqueous TCE, the biodegradation of WBC700-adsorbed TCE by Dhc 195 had a wider pH tolerance and required more VB 12 , due to the buffer effect and adsorption of WBC700, respectively. The obtained results could provide a cost-effective method of biochar regeneration for CAHs removal in groundwater.
研究领域:
环境科学
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微生物学
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DOI
高影响因子
ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
·
2017
·Vol. 24
·期 31
·24318-24326
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IF 2.741
Fu Xiaori,Brusseau Mark L.,Zang Xueke,Lu Shuguang,Zhang Xiang,Farooq Usman,Qiu Zhaofu,Sui Qian
This work demonstrates the impact of hydroxylamine hydrochloride (HAH) addition on enhancing the degradation of trichloroethene (TCE) by the citric acid (CA)-chelated Fe(II)-catalyzed percarbonate (SPC) system. The results of a series of batch-reactor experiments show that TCE removal with HAH addition was increased from approximately 57 to 79% for a CA concentration of 0.1 mM and from 89 to 99.6% for a 0.5 mM concentration. Free-radical probe tests elucidated the existence of hydroxyl radical (HO • ) and superoxide anion radical (O 2
•- ) in both CA/Fe(II)/SPC and HAH/CA/Fe(II)/SPC systems. However, higher removal rates of radical probe compounds were observed in the HAH/CA/Fe(II)/SPC system, indicating that HAH addition enhanced the generation of both free radicals. In addition, increased contribution of O 2
•- in the HAH/CA/Fe(II)/SPC system compared to the CA/Fe(II)/SPC system was verified by free-radical scavengers tests. Complete TCE dechlorination was confirmed based on the total mass balance of the released Cl − species. Lower concentrations of formic acid were produced in the later stages of the reaction for the HAH/CA/Fe(II)/SPC system, suggesting that HAH addition favors complete TCE mineralization. Studies of the impact of selected groundwater matrix constituents indicate that TCE removal in the HAH/CA/Fe(II)/SPC system is slightly affected by initial solution pH, with higher removal rates under acidic and near neutral conditions. Although HCO 3
− was observed to have an adverse impact on TCE removal for the HAH/CA/Fe(II)/SPC system, the addition of HAH reduced its inhibitory effect compared to the CA/Fe(II)/SPC system. Finally, TCE removal in actual groundwater was much significant with the addition of HAH to the CA/Fe(II)/SPC system. The study results indicate that HAH amendment has potential to enhance effective remediation of TCE-contaminated groundwater.
研究领域:
环境科学
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化学工程
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DOI
PubMed
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
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2024
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IF 8.1
Yinghao Shi,Dong Wang,Feilong Gao,Linan Liu,Qinglong Liu,Lan Wang,Jingchun Tang
The performance optimization of zero-valent iron (ZVI) based materials for reductive dechlorination remains challenging. After extensive research on sulfidation modification, the doping of heteroatom nitrogen (N) into ZVI for reductive dechlorination of chlorinated hydrocarbons (CHCs) becomes a new promising trend. In this study, surface modification of microscale ZVI (mZVI) was carried out by a facile ball milling method, and Fe–N(C) coated mZVI (abbreviated as N(C)-mZVI bm ) synthesized from different N sources of dimethylimidazole, urea and melamine were characterized. The effects of nitrogen-to-iron ratios (N/Fe), ball milling time and speed on the reductive dechlorination of trichloroethylene (TCE) were further investigated. A series of characterization and mechanistic analysis showed that the high reactivity of N(C)-mZVI bm with melamine as nitrogen source (abbreviated as N(C)-mZVI bm (M)) was attributed to the properties and thickness of its particle passivation layer, and faster electron transfer from the reduced iron species to the surface layer. In addition, N(C)-mZVI bm (M) exhibited great performance for dechlorination at a wide pH range of 3 to 11, due to alleviated passivation of the Fe 0 core under alkaline conditions by Fe–N(C). This study presents new ideas and evidences for the environmentally friendly synthesis of N-modified ZVI materials and their practical application in groundwater remediation.
研究领域:
环境科学
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材料科学
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DOI
高影响因子
ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
·
2017
·Vol. 24
·期 21
·17598-17605
·
IF 2.741
Wang Na,Jia Daqing,Jin Yaoyao,Sun Sheng-Peng,Ke Qiang
The present study investigated the degradation of trichloroethylene (TCE) in sand suspensions by Fenton-like reaction with magnetite (Fe 3 O 4 ) in the presence of various chelators at circumneutral pH. The results showed that ethylenediaminetetraacetic acid (EDTA) and nitrilotriacetic acid (NTA) greatly improved the rate of TCE degradation, while [S,S]-ethylenediaminedisuccinic acid (s,s-EDDS), malonate, citrate, and phytic acid (IP6) have minimal effects on TCE degradation. Quenching tests suggested that TCE was mainly degraded by hydroxyl radical (HO · ) attack, with about 90% inhibition on TCE degradation by the addition of HO · scavenger 2-propanol. The presence of 0.1–0.5% Fe 3 O 4 /sand ( w / w ) contributed to 40% increase in TCE degradation rates. In particular, the use of chelators can avoid high concentrations of H 2 O 2 required for the Fenton-like reaction with Fe 3 O 4 , and moreover improve the stoichiometric efficiencies of TCE degradation to H 2 O 2 consumption. The suitable concentrations of chelators (EDTA and NTA) and H 2 O 2 were suggested to be 0.5 and 20 mM, respectively. Under the given conditions, degradation rate constants of TCE were obtained at 0.360 h −1 with EDTA and 0.526 h −1 with NTA, respectively. Enhanced degradation of TCE and decreased usage of H 2 O 2 in this investigation suggested that Fenton-like reaction of Fe 3 O 4 together with NTA (or EDTA) may be a promising process for remediation of TCE-contaminated groundwater.
研究领域:
环境科学
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化学工程
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PubMed
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2025
·
IF 13.2
Wufeng Liu,Quanhua Xie,Tianlu Chen,Lu Ran,Zilin Nie,Yang Liu,Yuanyuan He,Haixing Chang,Najmeh Zare,Hassan Karimi-Maleh,Nianbing Zhong,Tejraj M. Aminabhavi
Photocatalytic optical hollow fibers (POHFs) coupled with spiral-shaped Cl − adsorption fibers are used to remove trichloroethylene (TCE) from wastewater. The POHFs are hollow quartz tubes coated with Ti 3 C 2 T x -doped oxygen vacancy (OV)-rich BiOBr (BiOBr-OV). The photocatalyst coating enhanced the excitation light intensity onto the photocatalytic fiber surface. The hetero-junction between Ti 3 C 2 T x and BiOBr-OV reduced the bandgap and broadened spectral absorption range of the composite photocatalyst. The material increased the production of reactive · O 2 - and •OH species, thereby improving the degradation of TCE. Spiral-shaped Cl − adsorption fibers comprised of polyethersulfone loaded with ethylenediaminetetraacetic acid-grafted metal–organic framework (MOF-808-EDTA). Tertiary amine groups (−R 3 N) of MOF-808-EDTA exhibited superior Cl − adsorption capabilities. As the Cl − ion indirectly quenches the free radicals, its removal reduced the inhibitory effect of the photocatalytic products, further enhancing the efficiency of TCE degradation and removing its degraded byproducts. TCE, chemical oxygen demand, and Cl − ion removal rates are 98.75, 69.15, and 99.22 %, respectively. Intimate coupling of photocatalysis and ion adsorption provided an effective solution for efficient removal of TCE, its degradation products, and Cl − ions from wastewater.
研究领域:
环境科学
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材料科学
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DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2017
·
IF 6.216
Xiang Zhang,Xiaogang Gu,Shuguang Lu,Mark L. Brusseau,Minhui Xu,Xiaori Fu,Zhaofu Qiu,Qian Sui
The enhancement effect of an environmentally friendly reducing agent, ascorbic acid (AA), on trichloroethene (TCE) degradation by Fe(III)-activated calcium peroxide (CP) was evaluated. The addition of AA accelerated the transformation of Fe(III) to Fe(II), and the complexation of Fe(III)/Fe(II) with AA and its products alleviated the precipitation of dissolved iron. These impacts enhanced the generation of reactive oxygen species (ROSs). Investigation of ROSs using chemical probe tests, electron paramagnetic resonance (EPR) tests, and radical scavenger tests strongly confirm large production of hydroxyl radicals (HO ) that is responsible for TCE degradation. The generation of Cl − from the degraded TCE was complete in the enhanced CP/Fe(III)/AA system. The investigation of solution matrix effects showed that the TCE degradation rate decreases with the increase in solution pH, while Cl − , SO 4 2− and NO 3 − anions have minor impact. Conversely, HCO 3 − significantly inhibited TCE degradation due to pH elevation and HO scavenging. The results of experiments performed using actual groundwater indicated that an increase in reagent doses are required for effective TCE removal. In summary, the potential effectiveness of the CP/Fe(III)/AA oxidation system for remediation of TCE contaminated groundwater has been demonstrated. Additional research is needed to develop the system for practical implementation.
研究领域:
环境科学
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化学
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PubMed
高影响因子
International Journal of Environmental Research and Public Health
·
2022
·Vol. 19
·期 10
·6299
·
IF 4.614
Yue Lang,Yanan Yu,Hongtao Zou,Jiexu Ye,Shihan Zhang
Trichloroethylene (TCE) is one of the most widely distributed pollutants in groundwater and poses serious risks to the environment and human health. In this study, sulfidated nanoscale zero-valent iron (S-nZVI) materials with different Fe/S molar ratios were synthesized by one-step methods. These materials degraded TCE in groundwater and followed a pathway that did not involve the production of toxic byproducts such as dichloroethenes (DCEs) and vinyl chloride (VC). The effects of sulfur content on TCE dechlorination by S-nZVI were thoroughly investigated in terms of TCE-removal efficiency, H2evolution, and reaction rate. X-ray diffraction (XRD) and X-ray Photoelectron Spectroscopy (XPS) characterizations confirmed Fe(0) levels in S-nZVI were larger than for zero-valent iron (nZVI). An Fe/S molar ratio of 10 provided the highest TCE-removal efficiencies. Compared with nZVI, the 24-h TCE removal efficiencies of S-nZVI (Fe/S = 10) increased from 30.2% to 92.6%, and the Fe(0) consumed during a side-reaction of H2evolution dropped from 77.0% to 12.8%. This indicated the incorporation of sulfur effectively inhibited H2evolution and allowed more Fe(0) to react with TCE. Moreover, the pseudo-first-order kinetic rate constants of S-nZVI materials increased by up to 485% compared to nZVI. In addition, a TCE degradation was proposed based on the variation of detected degradation products. Noting that acetylene, ethylene, and ethane were detected rather than DCEs and VC confirmed that TCE degradation followed β-elimination with acetylene as the intermediate. These results demonstrated that sulfide modification significantly enhanced nZVI performance for TCE degradation, minimized toxic-byproduct formation, and mitigated health risks. This work provides some insight into the remediation of chlorinated-organic-compound-contaminated groundwater and protection from secondary pollution during remediation by adjusting the degradation pathway.Keywords:S-nZVI;sulfidation;trichloroethylene;pathway;groundwater safety
研究领域:
环境科学
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化学
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PubMed
高影响因子
JOURNAL OF ENVIRONMENTAL ENGINEERING
·
2021
·Vol. 148
·期 1
·04021072
·
IF 1.86
Ting Su,Xiaoning Wang,Xinan Chen,Yan Cheng,Zhenkai Wang,Zhangxiong Wu,Winston Duo Wu,Sheng-Peng Sun
The ferric-nitrilotriacetate (Fe3+-NTA)-catalyzed homogenous Fenton-like reaction (i.e., Fe3+-NTA/H2O2) has received increasing interest for environmental applications, but its potential in degrading trichloroethylene (TCE) in groundwater still is not well known. The results of this study showed that Fe3+-NTA/H2O2 was more effective than other Fe3+-chelate/H2O2 processes (e.g., including ethylenediaminetetraacetate, ethylenediamine-N,N′-disuccinate, citrate, malonate, and tartrate) in degrading TCE in groundwater at natural pH (∼8.0). The effects of important parameters including the ratio of NTA∶Fe3+, and the dosages of Fe3+-NTA and H2O2 were investigated. Greater than 98% degradation efficiency of TCE in actual groundwater was obtained after 60 min of reaction time under the given conditions of NTA∶Fe3+=1.5∶1, 0.1 mM Fe3+-NTA, 5 mM H2O2, and pH 8.0. Hydroxyl radical (HO•) was responsible for the degradation of TCE, and the by-products were identified as formic acid and chloride ion (Cl−). Greater than 90% degradation efficiency of TCE in a sand column was achieved under dynamic conditions [0.5 mM Fe3+-NTA (1∶1.5), 4 mM H2O2, and hydraulic retention time of 4 h], resulting in stoichiometric ratios of ΔCl−∶ΔTCE and ΔTCE∶ΔH2O2 of ∼3∶1 and 4%, respectively. Compared with iron mineral (e.g., magnetite)-catalyzed Fenton-like processes, Fe3+-NTA/H2O2 led to much smaller consumption of H2O2 (at least 1 order of magnitude smaller). In addition, the buffering capacity of bicarbonate anions (HCO3−) in groundwater had a positive effect on the degradation of TCE by Fe3+-NTA/H2O2.
研究领域:
环境科学
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化学工程
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DOI
高影响因子
Journal of Environmental Sciences
·
2021
·
IF 5.565
Weilai Wang,Fan Zhang,Yunfei Zhang,Lei Xu,Yuansheng Pei,Junfeng Niu
Hydrodechlorination is a promising technology for the remediation of water body contaminated with trichloroethylene (TCE). In this work, the liquid-phase hydrogenation of TCE by Raney Ni (R-Ni) and Pd/C under an open system have been studied, in which nascent H 2 (Nas-H 2 ) generated in situ from the cathode acted as a hydrogen source. Experimental results showed that TCE was completely eliminate from the solution through the synergistic effects of hydrodechlorination and air flotation due to the formation of continuous micro/nano-sized Nas-H 2 bubbles from the cathode. Furthermore, the effects of inorganic anions and organic solvents on R-Ni and Pd/C hydrogenation activity were investigated, respectively. The results showed that NO 3 − and acetonitrile can form a competitive reaction with TCE; Sulfur with lone-pair electrons will cause irreversible poisoning to these two catalysts, and have a stronger inhibitory effect on Pd/C. This work helps to realize the separation of volatile halogenated compounds from water environment and provides certain data support for the choice of catalyst in the actual liquid-phase hydrogenation system.
研究领域:
环境科学
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催化化学
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DOI
PubMed
高影响因子
Journal of Environmental Chemical Engineering
·
2023
·
IF 7.7
Jingjing Zhan,Mengxue Ma,Xiujuan Zhang,Minghui Li,Yiwen Zhang,Hao Zhou,Tianxiang Wang
Sulfidated nanoscale zero-valent iron (S-nZVI) particles have demonstrated great potential in the remediation of trichloroethylene (TCE) due to their high reactivity and electron selectivity . However, very few studies have been carried out to investigate their application in salinity water or seawater. In this work, two kinds of S-nZVI particles were prepared through different methods including the chemical reduction method (CH-S-nZVI) and the bioprecipitation method (BP-S-nZVI), and then their performances in TCE remediation in seawater environment were thoroughly compared. The results suggested that the TCE removal by CH-S-nZVI particles in seawater is reduced compared to that in fresh water. However, the difference is negligible for BP-S-nZVI particles. It indicates that the seawater has a relatively strong inhibitory effect on the TCE degradation by CH-S-nZVI, but the inhibition for BP-S-nZVI is very weak. Furthermore, this work verified that sodium chloride and organic matters have obvious inhibitory effects on the TCE dichlorination, while coexisting ions such as NO 3 - , SO 4 2- and Mg 2+ are helpful to the degradation of TCE. The research proved that the performance of BP-S-nZVI particles in seawater is superior to CH-S-nZVI particles, providing a suitable candidate for the treatment of polluted aquifers in coastal and near-shore areas.
研究领域:
环境科学
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化学工程
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DOI
高影响因子
JOURNAL OF ENVIRONMENTAL MANAGEMENT
·
2019
·
IF 4.865
Yuyan Liu,Saran P. Sohi,Siyuan Liu,Junjie Guan,Jingyao Zhou,Jiawei Chen
To address inorganic and organic contaminants in the environment, economic new adsorbents are required. Here we test magnetic biochar for efficient capture of the typical pollutants Cr(VI) and trichloroethylene (TCE) from solution. We used a simple synthesis using 2M FeCl 3 solution and peanut hull biomass to prepare magnetic ZVI biochar at alternate pyrolysis temperatures between 650 and 800 °C. The physicochemical character of the biochars were assessed using X-ray diffraction (XRD) and the Brunauer-Emmett-Teller (BET) method for surface area. The magnetic ZVI biochars were highly effective in the removal of Cr(VI) and TCE. The most effective magnetic biochar produced at 800 °C was further examined using scanning electron microscopy (SEM), revealing a high and even loading of ZVI. After sorption the same magnetic biochar was examined by X-ray photoelectron spectroscopy (XPS) to ascertain the underlying mechanisms. The dependence of Cr(VI) capture on solution pH was also examined. Our interpretation suggests that when pH < pH zpc (2.5) electrostatic attraction and redox reactions dominated the adsorption of Cr(VI). When pH > pH zpc the removal process was controlled mainly by redox reaction and substitution of chromate anions for hydroxyl ( OH) groups. Capture of TCE in contrast involved hydrophobic partitioning, pore-filling and reductive degradation. Overall our results suggest that simple synthesis of magnetic ZVI biochar could offer an economic and effective option to address water contamination issues.
研究领域:
环境科学
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材料科学
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DOI
PubMed
高影响因子
WATER RESEARCH
·
2021
·
IF 11.236
Jia Deng,Enlai Gao,Feng Wu,Zhixiong You,Xiaozhong Li,Shuxian Gao,Li-Zhi Huang
Atomic hydrogen (H•) is highly reactive for the hydrodechlorination of trichloroethylene (TCE). In this work, we found that the coprecipitation of Ni 2+ and Fe 2+ at neutral pH led to an unprecedented catalytic generation of H•. The generated H• effectively dechlorinate TCE to nontoxic ethylene and ethane, and Fe 2+ is the only electron donor. The abundant adsorbed H• produced with a Ni/Fe ratio of 0.4 enhances hydrogen evolution reaction causing a low efficiency for hydrodechlorination. In contrast, the active absorbed H• is generated in the crystal lattice of Ni-Fe hydroxides with a Ni/Fe ratio of 3.0 causing highly efficient hydrodechlorination of TCE. This work not only reveals the mechanism of catalytic hydrodechlorination by Ni-Fe hydroxides at neutral pH, but also provides a novel approach to detoxify TCE in contaminated water using facile precipitated Ni-Fe hydroxides.
研究领域:
环境科学
·
催化化学
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DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）