Mechanistic role of nitrate anion in TCE dechlorination by ball milled ZVI and sulfidated ZVI: Experimental investigation and theoretical analysis

Gong, Li; Qi, Jianlong; Lv, Neng; Qiu, Xiaojiang; Gu, Yawei; Zhao, Jiawei; He, Feng

doi:10.1016/j.jhazmat.2020.123844

Cited by 40 publications

(8 citation statements)

References 59 publications

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“…Xu et al found that the iron (Fe 2+ , Fe 3+ ) and sulfur precursors (Na 2 S 2 O 4 , Na 2 S, and K 2 S 6 ) used for synthesis significantly affect the performance of nZVI and S-nZVI for the degradation of TCE, which may contribute to the large variability in reactivity observed among different studies. In addition, ball milling ,− or post synthesis with elemental sulfur seems to be superior sulfidation methods for the degradation of TCE with reported R values larger than 100, albeit with limited data available.…”

Section: Contaminant Transformationmentioning

confidence: 99%

“…This may explain the lack of correlation of R with the optimal [S/Fe] dosed of S-(n)ZVI obtained from the two-step method where relatively limited sulfur loading on the particle is achievable, but significant correlation of R with the optimal [S/Fe] dosed is found for those from one-step synthesis using Na 2 S 2 O 4 ( p < 0.05) where higher extent of sulfur loading is observed (SI Figure S2). Complete transformation of S 0 to FeS was observed during sulfidation of mZVI by ball milling and two-step sulfidation of mZVI with S 0 (i.e., [S/Fe] dosed = [S/Fe] particle = 0.1), ,,− which could partially explain its superior performance for the degradation of TCE (Figure A), because the reported optimal [S/Fe] dosed values from aqueous sulfidation are typically less than 0.1, resulting in even smaller [S/Fe] particle (SI Table S1). Thus, further optimization of S-(n)ZVI should aim to incorporate higher amount of sulfur or increase the sulfidation ratio in the particle phase to maximize its reactivity for contaminant transformation.…”

Section: Contaminant Transformationmentioning

confidence: 99%

“…Precipitation of Fe x S y , especially FeS 2 , after sulfidation increases the hydrophobicity of (n)ZVI, which makes the reactions with hydrophilic molecules (e.g., H 2 O, NO 3 – ) less favorable as shown experimentally by contact angle analysis and theoretically by DFT calculations, ,,,,,, resulting in improved degradation of hydrophobic TCE. ,, The increased hydrophobicity of S-nZVI has also been shown to be the main reason for the substantially reduced degradation of hydrophilic chloramphenicol (indicated by the octanol–water partition coefficient, log K ow = 0.37) and the increased degradation of the more hydrophobic florfenicol (log K ow = 1.14) compared to nZVI . But the significance of surface hydrophobicity or its contribution to the overall reactivity of S-(n)ZVI for the transformation of contaminant is still unclear and would likely vary for different type of contaminants.…”

Section: Contaminant Transformationmentioning

confidence: 99%

“…161 Both positive and negative effects of common anions in groundwater, including NO 3 − , Cl − , HCO 3 − , CO 3 2− , SO 4 2− , PO 4 3− , and HPO 4 2− , have been observed for the degradation of TCE by S-(n)ZVI, but not to large extent. 73,130,131,162 contaminants other than CHCs under both anoxic and oxic conditions (SI Table S5), which is attributed to the blocking of reactive surface sites by NOM limiting attachment of target compounds. 124 NOM, such as humic acid and rhamonolipid, has been reported to be extensively sorbed to the surface of nZVI, S-nZVI, and Pd-nZVI.…”

Section: Degradation Of Contaminantsmentioning

confidence: 99%

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Recent Advances in Sulfidated Zerovalent Iron for Contaminant Transformation

Garcia

Zhang

Ghoshal

et al. 2021

Environ. Sci. Technol.

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134

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2021 marks 10 years since controlled abiotic synthesis of sulfidated nanoscale zerovalent iron (S-nZVI) for use in site remediation and water treatment emerged as an area of active research. It was then expanded to sulfidated microscale ZVI (S-mZVI) and together with S-nZVI, they are collectively referred to as S-(n)ZVI. Heightened interest in S-(n)ZVI stemmed from its significantly higher reactivity to chlorinated solvents and heavy metals. The extremely promising research outcomes during the initial period (2011−2017) led to renewed interest in (n)ZVI-based technologies for water treatment, with an explosion in new research in the last four years (2018−2021) that is building an understanding of the novel and complex role of iron sulfides in enhancing reactivity of (n)ZVI. Numerous studies have focused on exploring different S-(n)ZVI synthesis approaches, and its colloidal, surface, and reactivity (electrochemistry, contaminant selectivity, and corrosion) properties. This review provides a critical overview of the recent milestones in S-(n)ZVI technology development: (i) clear insights into the role of iron sulfides in contaminant transformation and long-term aging, (ii) impact of sulfidation methods and particle characteristics on reactivity, (iii) broader range of treatable contaminants, (iv) synthesis for complete decontamination, (v) ecotoxicity, and (vi) field implementation. In addition, this review discusses major knowledge gaps and future avenues for research opportunities.

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Section: Contaminant Transformationmentioning

confidence: 99%

Section: Contaminant Transformationmentioning

confidence: 99%

Section: Contaminant Transformationmentioning

confidence: 99%

Section: Degradation Of Contaminantsmentioning

confidence: 99%

See 2 more Smart Citations

Recent Advances in Sulfidated Zerovalent Iron for Contaminant Transformation

Garcia

Zhang

Ghoshal

et al. 2021

Environ. Sci. Technol.

Self Cite

134

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“…其中天然有机物如腐殖酸等会抑制降解反应, 这主要是由于这些物质附着于界面上从而屏蔽了用于吸附和去除目标污染物的活性反应位点 [66] . [58,[67][68][69] . 对于水体中共存的其他重金属离子, 其对降解反应的影响取决于其与 Fe 0 之间的相互作用形式.…”

Section: 氯代烃污染物unclassified

Advance of Sulfidated Nanoscale Zero-Valent Iron: Synthesis, Properties and Environmental Application

Yang¹,

Liu²,

Liu³

et al. 2022

Acta Chimica Sinica

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Nanoscale zero-valent iron (nZVI) is one of the most extensively studied materials in the field of water environment remediation. But the limitations of easy agglomeration, oxidation and poor electronic selectivity restrict its practical application. After the sulfidation on the surface of nZVI, the sulfidated nanoscale zero-valent iron (S-nZVI) can be formed, which can not only enhance the dispersion and stability, but also improve the electronic selectivity, thus becoming the hot spot recently. The synthesis methods, physiochemical properties and practical performances of S-nZVI are discussed detailedly in this review. Firstly, the effects of synthesis methods on the physiochemical properties of S-nZVI are summarized, which focus on adjusting the synthesis conditions (sulfidation sequence, sulfur precursors, S/Fe, etc.) to change the microstructure and chemical states of interface elements of S-nZVI (actual S/Fe, sulfur distribution, FeSx morphologies, etc.). And then the macro-properties (hydrophilicity/hydrophobicity, hydrogen evolution, conductivity, etc.) will be altered correspondingly, which will cause the directional removal of organic pollutants and heavy metal pollutants. Additionally, the research progress of S-nZVI in the removal of chlorinated hydrocarbons, antibiotics, nitrobenzene organics and heavy metals are discussed concretely and the future research directions are analyzed as well.

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Incorporation of N-doped biochar into zero-valent iron for efficient reductive degradation of neonicotinoids: mechanism and performance

Li,

Zhang,

Zhang

et al. 2023

Biochar

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The extensive use of neonicotinoids on food crops for pest management has resulted in substantial environmental contamination. It is imperative to develop an effective remediation material and technique as well as to determine the evolution pathways of products. Here, novel ball-milled nitrogen-doped biochar (NBC)-modified zero-valent iron (ZVI) composites (named MNBC-ZVI) were fabricated and applied to degrading neonicotinoids. Based on the characterization results, NBC incorporation introduced N-doped sites and new allying heterojunctions and achieved surface charge redistribution, rapid electron transfer, and higher hydrophobicity of ZVI particles. As a result, the interaction between ZVI particles and thiamethoxam (a typical neonicotinoid) was improved, and the adsorption–desorption and reductive degradation of thiamethoxam and ·H generation steps were optimized. MNBC-ZVI could rapidly degrade 100% of 10 mg·L−1 thiamethoxam within 360 min, its reduction rate constant was 12.1-fold greater than that of pristine ZVI, and the electron efficiency increased from 29.7% to 57.8%. This improved reactivity and selectivity resulted from increased electron transfer, enhanced hydrophobicity, and reduced accumulation of iron mud. Moreover, the degradation of neonicotinoids occurred mainly via nitrate reduction and dichlorination, and toxicity tests with degradation intermediates revealed that neonicotinoids undergo rapid detoxification. Remarkably, MNBC-ZVI also presented favorable tolerance to various anions, humic acid, wastewater and contaminated soil, as well as high reusability. This work offers an efficient and economic biochar-ZVI remediation technology for the rapid degradation and detoxification of neonicotinoids, significantly contributes to knowledge on the relevant removal mechanism and further advances the synthesis of highly reactive and environmentally friendly materials. Graphical Abstract

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Mechanistic role of nitrate anion in TCE dechlorination by ball milled ZVI and sulfidated ZVI: Experimental investigation and theoretical analysis

Cited by 40 publications

References 59 publications

Recent Advances in Sulfidated Zerovalent Iron for Contaminant Transformation

Recent Advances in Sulfidated Zerovalent Iron for Contaminant Transformation

Advance of Sulfidated Nanoscale Zero-Valent Iron: Synthesis, Properties and Environmental Application

Incorporation of N-doped biochar into zero-valent iron for efficient reductive degradation of neonicotinoids: mechanism and performance

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