Journal of Water Process Engineering
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2026
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IF 6.6
Xiang Luo,Hongwei Chen,Hongjian Shen,Ling Zhang,Jinbo Chen,Shuai Liu,Bo Gao,Honglei Zhang,Yawei Gu
Zero-valent iron (ZVI) technology is regarded as one of the most efficient approaches for remediating groundwater contaminated with chlorinated hydrocarbons (CHCs). Despite its highly reactive nature, the corrosion of ZVI in aqueous solution readily results in surface passivation, which diminishes its reactivity. ZVI doped with heteroatoms such as carbon (C), nitrogen (N), and sulfur (S) has displayed excellent performance in trichloroethylene (TCE) degradation. Nevertheless, the effects of these heteroatoms on ZVI materials, along with their various degradation mechanisms, remains ambiguous. In this study, C-mZVI bm , N-mZVI bm , and S-mZVI bm were prepared, respectively, via a mechanochemical method and utilized for TCE degradation. The dechlorination reaction facilitated by each material was thoroughly investigated both theoretically and experimentally, focusing on TCE adsorption affinity, the dechlorination process, hydrogen evolution reaction (HER), electron efficiency, and lifetime. Among the three materials, S-mZVI bm exhibited 100% TCE removal in less than 24 h., as well as improved electron efficiency and lifetime, primarily attributed to its high TCE adsorption energy and the suppression of HER. These integrated theoretical and experimental results indicate that S-mZVI bm nanoparticles are a promising and innovative material for in situ groundwater TCE remediation.
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Journal of Environmental Chemical Engineering
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2023
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IF 7.7
Tianwen Zheng,Daibing Hou,Naijin Wu,Moxi Wang,Nan Luo,Huilong Luo,Wenpeng Leng,Peizhong Li,Wenxia Wei
Microbial induced calcium carbonate precipitation (MICP) is a green and environmentally friendly technology . Herein, porous biological CaCO 3 was prepared by MICP technology and then used as the carrier material for nZVI to prepare CaCO 3 @nZVI composite. Afterwards, the various properties of the CaCO 3 @nZVI composite were methodically characterized. Subsequently, the adsorption kinetic equation and adsorption isotherm model of TCE were carefully investigated, and the CaCO 3 @nZVI composite dosage, initial pH, temperature, aging time and the number of cycles on the TCE removal efficiency were examined. Finally, the degradation mechanism of TCE by CaCO 3 @nZVI composite was revealed. The results showed that nZVI particles were successfully supported on the biological CaCO 3 surface, and the specific surface area of the CaCO 3 @nZVI composite was 52.641 m 2 /g, which was much higher than that of bare nZVI (8.757 m 2 /g). The adsorption kinetics of CaCO 3 @nZVI composite for TCE removal was conformed to the pseudo-second-order kinetic equation, and Freundlich model was more appropriate as the adsorption isotherm model. The optimal conditions for the TCE removal were obtained to be 0.24 g/L CaCO 3 @nZVI composite dosage, 25 ℃, and initial pH of 7.0, respectively. Furthermore, the CaCO 3 @nZVI composite exhibited good stability and reusability. The main degradation products of TCE by CaCO 3 @nZVI composite were acetylene, ethylene, and ethane, and the synergistic effects of adsorption and degradation were the main mechanisms of TCE removal. Generally, this paper provides experimental support for the selection of nZVI carrier materials, which is useful for promoting the development and advancement of green repair materials.
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SEPARATION AND PURIFICATION TECHNOLOGY
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2025
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IF 9
Haoran Tian,Jia Xin,Jiahui Lu,Weiran Meng,Yihan Wang,Qianyi Zhou
In-situ biogenic sulfidation of microscale zero-valent iron (mZVI) is an efficient and green method to enhance its dechlorination in groundwater. However, for practical field applications, the technology must maintain long-term effectiveness. At present, the performance evolution of aged biogenic sulfidated mZVI (BS-mZVI), especially regarding the influence of particle size, remains unclear and needs further investigation. In this study, BS-mZVI with two particle sizes (7 μm and 30 μm) was aged for 15, 30, and 45 days and systematically compared. The results showed that smaller particles (7 μm) achieved rapid initial trichloroethylene (TCE) removal (95 % in 6 days), but their reactivity declined with prolonged aging ( k SA = 1.12 × 10 −2 L·m −2 ·d −1 with 45-day aging). Conversely, larger particles (30 μm) exhibited improved reactivity over time, reaching a k SA of 1.57 × 10 −2 L·m −2 ·d −1 after 45-day aging while maintaining over 92 % TCE removal. Surface characterization revealed that aged BS-mZVI (7 μm) developed increased hydro(oxide) passivation layers (Fe 2 O 3 /FeOOH) from 15 to 45 days of aging, which decreased its reactivity. In contrast, aged BS-mZVI (30 μm) gradually formed conductive FeS x shells during aging, retaining hydrophobicity and enhancing reactivity. Metagenomic analysis further revealed that with prolonged aging (15 to 45 days), the 30 μm BS-mZVI enriched sulfate-reducing bacteria (SRB) and iron-reducing bacteria (IRB), accompanied by higher abundances of key functional genes involved in sulfate and iron reduction, thereby promoting sustained TCE degradation. These particle size-dependent results demonstrate that smaller BS-mZVI enables rapid TCE decontamination, whereas larger particles offer prolonged reactivity, helping to choose materials based on the needed remediation timeframe required in applications.
研究领域:
环境科学
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地下水修复
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纳米材料应用
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环境微生物学
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污染物降解
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CHEMICAL ENGINEERING JOURNAL
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2017
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IF 6.216
Fenglin Tang,Jia Xin,Tianyuan Zheng,Xilai Zheng,Xiupei Yang,Olaf Kolditz
Uncertainties of aging after the injection of microscale zero valent iron (mZVI) into subsurface hinder the widespread application of this technology into in-situ groundwater remediation. As TCE removal by mZVI is usually accompanied by mZVI anaerobic reaction with water, this study investigated the hydrogen evolution kinetics, TCE removal performance, and electron efficiency (EE) of mZVI particles under single and combined effects of organic geochemical constituents (humic acid (HA)), inorganic constituents (hardness (Ca 2+ ) and alkalinity (HCO 3 − )) in groundwater. The results showed that both H 2 generation and TCE removal were enhanced in the presence of HA (5–20 mg L −1 as DOC), and significant delay of aging precipitates formation was supported by SEM-EDS, XRD and XPS depth-profiling characterization. With increasing Ca 2+ -HCO 3 − concentrations (0.4–2 mM), the mZVI corrosion were inhibited for the formation of a thin compact passive film on mZVI surface. Furthermore, in co-presence of organic and inorganic constituents, the negatively-impacted iron corrosion kinetics suggested that promotional effects of organic constituents were dwarfed by the inhibitory effects of inorganic constituents. In addition, the EE values in different systems ranged among 1.31–7.40%, and decreased significantly with time. Hence, these findings provide insight into aging mechanism and performance prediction of mZVI under different groundwater geochemical conditions.
研究领域:
环境科学
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污染治理
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CHEMICAL ENGINEERING JOURNAL
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2024
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IF 13.3
Yanping Cui,Haodong Yang,Xian Xiang,Shibo Zhao,Qiao Huang,Zhaoqiang Huang
A modified graphite felt (MGF) was prepared with carbon black (CB) and polytetrafluoron (PTFE) for cathodic electrochemical H 2 O 2 production, which was used in a flow-through cathodic electro-Fenton reactor to degrade chlorinated hydrocarbons. Cathode electrode was floating on aqueous surface and 369.1 mg/L H 2 O 2 could be produced after 1 h 150 mA power applied without O 2 aeration. The main O 2 source for H 2 O 2 production was confirmed from air with this floating position. In a 2.0 L flow-through cathodic electro-Fenton system, 95.97 % degradation efficiency for 5.0 mg/L trichloroethylene (TCE) was achieved in 90 min with 13.4 mL/min influent rate. Reducing the reactor volume to 0.14 L, 5.0 mg/L TCE could be degraded completely in 10 min with continuous 4 L influent. The mixed chlorinated hydrocarbons (TCE, cis -1,1-dichloroethylene, 1,2-dichloroethane, and dichloromethane) were also rapidly degraded in 20 min. The flow-through cathodic electro-Fenton reactor presented excellent degradation ability for chlorinated hydrocarbons with a smaller volume. In the simulated sand tank system, after continuously operated 27 days, H 2 O 2 concentration in electrode well was still remained at 80 mg/L. In the contaminated field in Tianjin, China, H 2 O 2 yield of MGF in groundwater could keep at about 60 mg/L after 220 min operating.
研究领域:
环境科学
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电化学工程
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