JOURNAL OF HAZARDOUS MATERIALS
·
2023
·
IF 13.6
Xin Zhang,Qingling Fu,Hongqing Hu,Jun Zhu,Yonghong Liu
The co-oxidation of Fe(II) and As(III) occurs under aerobic conditions , and Fe(II) may largely determine the fate of As(III), but the effect of Fe(II) on the As(III) oxidation is barely explored. In this research, the limiting and driving roles of Fe(II) in As(III) oxidation were systematically studied through batch kinetic studies in combination with X-ray photoelectron spectroscopy (XPS) depth profiling, scanning electron microscopy and energy dispersive X-ray spectrometry (SEM-EDS), and quenching experiments. The results showed that As(III) oxidation efficiency increased with the increase of Fe/As molar ratio (from 63.1% to 98.3%), but decreased with the increase of pH (from 96.0% to 44.2%) and the increase of air flow rate (from 88.1% to 75.1%). The Fe(II) oxidation rate increased with the increase of pH and air flow rate. When Fe(II) was oxidized rapidly, As(III) was more likely to be immobilized in the “inner sphere” of formed Fe (hydr)oxides, limiting As(III) oxidation. On the other hand, Fe(II) was oxidized to produce Fe (hydr)oxides to adsorb or fix As(III); meanwhile, the ROS generated by Fenton-like reaction of Fe(II) promoted As(III) oxidation, especially, •O 2 − and H 2 O 2 were important ROS that drove the As(III) oxidation. These findings might provide a new insight for Fe(II) and As(III) geochemistry cycling in naturally occurring environment.
研究领域:
环境科学
·
地球化学
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DOI
PubMed
高影响因子
WATER RESEARCH
·
2023
·
IF 12.8
Tao Yang,Linqian An,Ge Zeng,Maoju Jiang,Juan Li,Changyu Liu,Jianbo Jia,Jun Ma
The widespread occurrence of p -arsanilic acid ( p -ASA) in natural environments poses big threats to the biosphere due to the generation of toxic inorganic arsenic (i.e., As(III) and As(V), especially As(III) with higher toxicity and mobility). Oxidation of p -ASA or As(III) to As(V) followed by precipitation of total arsenic using Fe-based advanced oxidation processes demonstrated to be a promising approach for the treatment of arsenic contamination. This study for the first time investigated the efficiency and inherent mechanism of p -ASA and As(III) oxidation by Fe(II)/peracetic acid (Fe(II)/PAA) and PAA processes. p -ASA was rapidly degraded by the Fe(II)/PAA process within 20 s at neutral to acidic pHs under different conditions, while it was insignificantly degraded by PAA oxidation alone. Lines of evidence suggested that hydroxyl radicals and organic radicals generated from the homolytic O O bond cleavage of PAA contributed to the degradation of p -ASA in the Fe(II)/PAA process. p -ASA was mainly oxidized to As (V), NH 4 + , and p -aminophenol by the Fe(II)/PAA process, wherein the aniline group and its para position were the most vulnerable sites. As(III) of concern was likely generated as an intermediate during p -ASA oxidation and it could be readily oxidized to As(V) by the Fe(II)/PAA process as well as PAA alone. The in-depth investigation demonstrated that PAA alone was effective in the oxidation of As(III) under varied conditions with a stoichiometric molar ratio of 1:1. Efficient removal (> 80%) of total arsenic during p -ASA oxidation by Fe(II)/PAA process or during As(III) oxidation by PAA process with additional Fe(III) in synthetic or real waters were observed, mainly due to the adsorptive interactions of amorphous ferric (oxy)hydroxide precipitates. This study systematically investigates the oxidation of p -ASA and As(III) by the Fe(II)/PAA and PAA processes, which is instructive for the future development of arsenic remediation technology.
研究领域:
环境科学
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化学
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DOI
PubMed
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2016
·
IF 5.31
Yunfei Xue,Xiaogang Gu,Shuguang Lu,Zhouwei Miao,Mark L. Brusseau,Minhui Xu,Xiaori Fu,Xiang Zhang,Zhaofu Qiu,Qian Sui
The ability of Fe(II)-activated calcium peroxide (CaO 2 ) to remove benzene is examined with a series of batch experiments. The results showed that benzene concentrations were reduced by 20–100% within 30 min. The magnitude of removal was dependent on the CaO 2 /Fe(II)/Benzene molar ratio, with much greater destruction observed for ratios of 4/4/1 or greater. An empirical equation was developed to quantify the destruction rate dependence on reagent composition. The presence of oxidative hydroxyl radicals (HO ) and reductive radicals (primarily O 2 − ) was identified by probe compound testing and electron paramagnetic resonance (EPR) tests. The results of the EPR tests indicated that the application of CaO 2 /Fe(II) enabled the radical intensity to remain steady for a relatively long time. The effect of initial solution pH was also investigated, and CaO 2 /Fe(II) enabled benzene removal over a wide pH range of 3.0–9.0. The results of radical scavenging tests showed that benzene removal occurred primarily by HO oxidation in the CaO 2 /Fe(II) system, although reductive radicals also contributed. The intermediates in benzene destruction were identified to be phenol and biphenyl. The results indicate that Fe(II)-activated CaO 2 is a feasible approach for treatment of benzene in contaminated groundwater remediation.
研究领域:
环境科学
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化学工程
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产品关联
DOI
PubMed
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2021
·
IF 13.273
Jinbin Lin,Yuye Hu,Junyang Xiao,Yixin Huang,Mengyun Wang,Haoyu Yang,Jing Zou,Baoling Yuan,Jun Ma
Fe(II)/peracetic acid (Fe(II)/PAA) process exhibits a great potential in abatement of micropollutants because of the fast reaction between Fe(II) and PAA. Similar to Fenton system, the slow reduction from Fe(III) to Fe(II) leads to the high dosage of Fe(II) in Fe(II)/PAA process. This study introduced 2,2′-azino-bis(3-ethylbenz- -othiazoline-6-sulfonate) (ABTS) as electron shuttle to improve the oxidation capacity of Fe(II)/PAA process by accelerating the redox cycle of Fe(III)/Fe(II). ABTS/Fe(II)/PAA process possessed high elimination efficiency of diclofenac in acidic conditions. Alcohols quenching experiments confirmed that ABTS •+ was the primary reactive species responsible for diclofenac elimination, although Fe IV O 2+ and carbon-centered radicals (R-O • ) also existed in ABTS/Fe(II)/PAA process. ABTS •+ was generated via various pathways, including the reactions of ABTS with Fe(III), Fe IV O 2+ and R-O • . ABTS was not an ideal electron shuttle because R-O • could decompose partial ABTS •+ to sulfoxides and sulfones. Two possible degradation pathways of diclofenac were proposed based on the detected transformation products. ABTS/Fe(II)/PAA process was highly-efficient for diclofenac elimination in underground water and reservoir water, while high concentration of humic acid had inhibition effect on diclofenac degradation. The present study provides a promising way to alleviate the intrinsic drawbacks of Fe(II)/PAA process and might advance its potential application in water treatment.
研究领域:
环境科学
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水处理技术
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产品关联
DOI
高影响因子
WATER RESEARCH
·
2022
·
IF 13.4
Siqi Liu,Andrey M. Kuznetsov,Weiqing Han,Alexei N. Masliy,Gregory V. Korshin
Methylated arsenic species are ubiquitous in the environment and resistant to removal by conventional treatment technologies. This study addressed this challenge based on the examination of the removal of dimethylarsinic acid (DMA) in a system that combines zerovalent iron (ZVI) and powdered activated carbon (PAC). The removal of DMA in the ZVI/PAC system was compared to that by coagulation, adsorption, electrochemical and Fenton oxidations, and other conventional methods. While only the electrochemical oxidation using a PbO 2 /Sb-SnO 2 /Ti anode allowed removing up to 60% DMA at several hours-long treatment times, the removal of DMA in the ZVI/PAC system containing 10 g/L ZVI and 2.5 g/L PAC with an initial pH of 2.0 was 95% for a 30 min reaction time. Specific roles of PAC, ZVI and its oxidation products in DMA removal were examined based on the spectroscopic data and quantum chemical modeling for the DMA/Fe(II) and DMA/Fe(III) systems. These methods demonstrated the formation of moderately strong DMA/Fe(II) and DMA/Fe(III) complexation. These results and relevant kinetic data were interpreted to indicate that the removal of DMA is governed by the rapid generation of Fe 2+ ions released as a result of accelerated ZVI corrosion in the galvanic ZVI/PAC microcells and ensuing formation of DMA/ Fe 2+ complexes that are readily adsorbed by PAC.
研究领域:
环境科学
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化学工程
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水处理
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DOI
PubMed
高影响因子
Environmental Science-Nano
·
2024
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IF 5.8
Shengnan Zhang,Lingyi Li,Junxue Li,Wei Cheng
Hematite displays diverse crystal structures and often coexists with Fe(II), both of which are crucial in controlling the fate and mobility of Cr(VI). However, the mechanisms underlying Cr(VI) removal in the presence of Fe(II) on various hematite facets remain elusive. This study aims to elucidate the facet-dependent reactivity of hematite nanocrystals in conjunction with Fe(II) for the removal of Cr(VI) from aqueous solutions. Hematite nanoplates (HNPs), predominantly composed of {001} facets, and nanorods (HNRs), exposing both {001} and {110} facets, were synthesized and characterized. Their Cr(VI) removal capabilities were evaluated in hematite–Cr(VI) and hematite–Fe(II)–Cr(VI) systems, as well as the Fe(II)–Cr(VI) system. The adsorption of Fe(II) and Cr(VI) on hematite surfaces was highly dependent on the crystal facets and pH, with HNRs demonstrating superior Cr(VI) adsorption over HNPs, especially under acidic conditions. Neutral pH favored Fe(II)–Cr(VI) redox reactions and Fe(II) adsorption. The hematite–Fe(II) couple displayed a synergistic effect in removing Cr(VI) under acidic conditions, which was not observed under neutral conditions. The presence of Fe(II) notably enhanced Cr(VI) adsorption onto hematite, and bound Fe(II) facilitated electron transfer, accelerating Cr(VI) reduction. HNRs–Fe(II) exhibited higher Cr(VI) removal efficiency than HNPs–Fe(II) due to their lower free corrosion potential and improved electron transport properties. This research underscores the potential of facet engineering in optimizing hematite nanocrystals for environmental remediation, specifically in Cr(VI)-contaminated environments.
研究领域:
环境科学
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材料科学
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产品关联
DOI
高影响因子
CHEMICAL GEOLOGY
·
2024
·
IF 3.6
Kuan Cheng,Yunlu Yin,Ying Wang,Guoyong Huang,Dandan Pan,Milan Wang,Xuxin Song,Tongxu Liu,Xiaomin Li
Microbial Fe(II) oxidation is mainly mediated by the outer-membrane proteins that contain c -type cytochromes ( c- Cyts), and the widespread Fe(II)-oxidizing bacteria are usually subjected to fluctuations between oxic and anoxic conditions. However, it remains unclear how oxygen affects the redox dynamics of c- Cyts by Fe(II), particularly in the presence of organic ligands that are widely distributed in the environment. Here, the reduction of a model heme-containing c- Cyts by Fe(II) was investigated in the absence and presence of organic ligands (i.e., citrate and acetate) at pH 5.5 under anoxic and oxic conditions . The kinetic results showed that c- Cyts reduction was enhanced by citrate and acetate under anoxic conditions, and the enhancement by citrate was more pronounced than that by acetate. The speciation calculation and cyclic voltammetry results suggested that the proportions of Fe(II)-Citrate complexes were much higher than those of Fe(II)-Acetate complex, but the addition of acetate and citrate caused minor changes in redox potential of Fe(II)/Fe(III) species. Further analysis using quantum chemical computation demonstrated that the formation of Fe(II)-Heme complexes via lateral binding to the carboxyl group of c- Cyts was more stable than those via replacing the S-linked axial ligand of heme, with the recombination energy with Heme ranking as Fe(II)-Citrate < Fe(II)-Acetate < Fe(II). Therefore, the stronger complexation of Fe(II)-Citrate and its lower recombination energy with c- Cyts drive the enhanced c- Cyts reduction under anoxic conditions. By contrast, the c- Cyts reduction by Fe(II) and Fe(II)-ligand was inhibited under oxic conditions. The electron spin resonance characterization indicated that both O 2 − • and OH• radicals were produced in the system of c- Cyts with Fe(II) or Fe(II)-ligand under oxic conditions and the signals were higher with Fe(II)-ligand than those with Fe(II). These reactive oxygen species were proposed to enable a re-oxidation of the c- Cyts that was reduced by Fe(II) or Fe(II)-ligand, causing an inhibitory effect on the observed c- Cyts reduction and forming more reactive oxygen species . Our findings shed light on the important roles of Fe(II)-ligand-heme complexation and reactive oxygen species in the interaction between Fe(II) and c- Cyts, which deepen the understanding of microbial/enzymatic Fe(II) oxidation under oxic conditions at the molecular level.
研究领域:
微生物学
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生物化学
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产品关联
DOI
高影响因子
JOURNAL OF COLLOID AND INTERFACE SCIENCE
·
2019
·
IF 6.361
Jie Cao,Jin Huang,Huaping Dong,Jianfa Li,Jianxin Shou,Yimin Li
Surfactants are easily accumulated in groundwater, sediment, and aquifers, due to their excessive use in household, industrial, and agricultural processes. These residual surfactants are expected to influence the transformation and fate of organic contaminants by Fe(II) sorbed on iron oxides in anaerobic environments. Here, we investigated the effects of various surfactants including nonionic TX-100, anionic SDBS and bio-surfactant saponin on the removal of nitrobenzene (NB) by Fe(II) sorbed on goethite (goethite/Fe(II)) through batch experiments. We also elucidated the mechanism behind the effects by XPS, XRD , and determination of the amounts of sorbed Fe(II) on goethite. The results showed that the presence of TX-100 improved NB removal from 77.2% in the absence of surfactant, to 93.8% within 6 h, and improved the removal rate by about 1.3 times. In contrast, the presence of SDBS decreased the removal efficiency to 45.5%, and the presence of saponin nearly inhibited the removal of NB completely. The removed NB was finally nearly reduced to aniline in the absence or presence of surfactants, except in the case of saponin. The amounts of sorbed Fe(II) listed in the sequence as goethite/Fe(II)+TX-100 > goethite/Fe(II) > goethite/Fe(II)+SDBS > goethite/Fe(II)+saponin, and this order negatively correlated with that in the redox potential of these systems. These results confirmed that the presence of surfactants influenced the sorption of Fe(II) on goethite and changed the reactivity of goethite/Fe(II) for NB removal. This finding will promote a clear understanding of the impact of coexisting surfactants on the transformation and fate of organic contaminants in real anaerobic environments.
研究领域:
环境科学
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化学
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产品关联
DOI
PubMed
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2015
·
IF 4.321
Zhouwei Miao,Xiaogang Gu,Shuguang Lu,Dionysios D. Dionysiou,Souhail R. Al-Abed,Xueke Zang,Xiaoliang Wu,Zhaofu Qiu,Qian Sui,Muhammad Danish
The performance of chelated Fe(II)-based catalyzed sodium percarbonate (SPC) stimulating the degradation of perchloroethylene (PCE) in aqueous solution was investigated using six different chelating agents (CA), namely, citric acid monohydrate (CIT), oxalic acid (OA), l -ascorbic acid (ASC), ethylenediaminetetraacetic acid (EDTA), trisodium citrate 2-hydrate (CIT-Na 3 ), and EDTA-Na 2 , at CA/Fe(II)/SPC/PCE molar ratios of 2/4/4/1, 4/4/4/1 and 8/4/4/1. The results indicated that the addition of CIT and OA significantly enhanced the PCE degradation. In addition, investigations using free radical probe compounds and radical scavengers revealed that PCE was primarily degraded by HO radical oxidation in Fe(II)/SPC, CIT/Fe(II)/SPC, and OA/Fe(II)/SPC systems and O 2 − also participated in the degradation of PCE in CIT/Fe(II)/SPC and OA/Fe(II)/SPC systems. The intensity of HO detected by electron paramagnetic resonance (EPR) in CIT/Fe(II)/SPC and OA/Fe(II)/SPC systems indicated that the addition of CIT or OA indeed enhanced the continuous production of HO and enabled the intensity of HO to be more stable. The results demonstrated that CIT and OA significantly improved the PCE degradation efficiency by increasing the concentration of Fe(II) and maintaining the concentration of HO radicals in solution. In conclusion, chelated Fe(II)-based catalyzed SPC oxidation process shows enormous practical prospects for the remediation of PCE-contaminated groundwater because of the effectiveness without pre-adjusting the solution pH and complete mineralization in Fe(II)/SPC, CIT/Fe(II)/SPC and OA/Fe(II)/SPC systems.
研究领域:
环境科学
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化学
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产品关联
DOI
高影响因子
WATER RESEARCH
·
2018
·
IF 7.051
Wei Ding,Jing Xu,Tao Chen,Chengshuai Liu,Jinjun Li,Feng Wu
Previous studies have shown that the oxidation of Fe(II) by molecular oxygen can lead to the co-oxidation of As(III) at neutral pH. However, the mechanism of As(III) oxidation in the presence of Fe(II) with respect to the interaction between As(III) and Fe(II) is still unclear. In this work, we examined the oxidation of As(III) in the presence of Fe(II) in air-saturated water, which is affected by pH, co-existing phosphate, and scavengers ( tert -butanol, superoxide dismutase, catalase and dimethylsulfoxide). Results confirm that the formation of the Fe(II)–As(III) complex (formation constant, K Fe(II)–As(III) = 10 3.86 M –1 ) plays an extremely important role in the initial stage of As(III) oxidation at pH 7.25. The oxidation of Fe(II)–As(III) promotes the production of H 2 O 2 and colloidal ferric hydroxide. H 2 O 2 reacts with the Fe(II)–As(III) complex through oxidizing Fe(II) to Fe(IV), which then causes the partial oxidation (ca. 50%) of As(III). The other part of As(III) oxidation by H 2 O 2 occurs, in the form of Fe(III)–As(III) complex, through direct electron transfer from As(III) to H 2 O 2 but not through Fe(IV). This work provides new mechanistic insight into arsenic and iron redox chemistry in the environment and furthers our understanding of Fenton reactions at neutral pH.
研究领域:
环境化学
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氧化还原化学
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水处理
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产品关联
DOI
PubMed
高影响因子
Analytical Methods
·
2014
·Vol. 6
·期 19
·7973-7977
·
IF 1.938
Yingfeng Qin,Liangliang Zhang,Gaojie Ye,Shulin Zhao
A homogeneous label-free colorimetric sensing strategy for bleomycin (BLM) assay was developed on the basis of BLM enhanced Fe(II)–H2O2–ABTS reaction. Fe(II) exhibits a catalytic effect on H2O2-mediated oxidation of ABTS by Fenton chemistry. BLM·Fe(II) complex possessed a significantly higher catalytic ability than Fe(II) probably because of the further formation of more active “activated oxo-iron-bleomycin complex”. The present method was convenient without any complicated chemical synthesis, modification, or tedious experimental procedures. Analysis results can be seen with the naked eye and monitored by UV-vis spectra. The peak absorbance exhibits a linear relationship with BLM concentrations from 25 nM to 1 μM, and a detection limit of 16 nM can be achieved. The designed colorimetric strategy may provide a promising alternative for BLM detection in clinical samples.
研究领域:
分析化学
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生物医学
·
临床检验
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产品关联
DOI
高影响因子
DIAMOND AND RELATED MATERIALS
·
2025
·
IF 5.1
Miaomiao Chen,Meng Zhou,Caihong Mao,Chunchao Wu,Shujie Pang,Xudong Yang
Fluorescent hydrogel were developed for Fe(II) detection to overcome the shortcomings of simple carbon dots solutions (CDs), which are difficult to store and use. CDs were prepared using the hydrothermal synthesis with o -phenylenediamine and dopamine as the carbon sources. Fluorescent hydrogel (CACDs) were obtained by doping CDs in and impregnating them with carboxymethyl cellulose hydrogel (CA) prepared using crosslinked carboxymethyl cellulose (CMC), which was grafted using acrylamide as the substrate. Using CDs and CA as a fluorescent group and a backbone, respectively, enhanced the fluorescence performance and facilitated Fe(II) detection. The surface groups, elemental composition and optical properties of the prepared CDs and CACDs were systematically studied using FTIR, XRD, UV–Vis and fluorescence spectrometer. The effects of pH, temperature, NaCl salt solution and UV irradiation on the stability of CDs in the hydrogel were discussed. CACDs exhibited strong, bright yellow fluorescence with a fluorescence intensity 4.35 times higher than that of CDs. CACDs can be used as fluorescent probes to realise real-time detection of Fe(II) at a low detection limit (0.22 μM), allowing them to be employed for Fe(II) detection in real water samples. CACDs had stable adsorption properties for Fe(II). The adsorption process of metal ions conformed to pseudo-second order kinetics and Langmuir model, respectively. Therefore, CACDs are expected to be bifunctional materials for effective detection and removal of Fe(II).
研究领域:
材料科学
·
环境科学
·
分析化学
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产品关联
DOI
高影响因子
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