WATER RESEARCH
·
2022
·
IF 13.4
Liping Fang,Baolin Gao,Fangbai Li,Kai Liu,Jialin Chi
The incorporation of secondary metal atoms into iron oxyhydroxides may regulate the surface chemistry of mediating electron transfer (ET) and, therefore, the biogeochemical pollutant processes such as arsenic (As) in the subsurface and soils. The influence of incorporating two typical metals (Cu and Zn) into a specific {001} hematite facet on O 2 activation by surface-bound Fe(II) was addressed. The results showed that Cu-incorporated hematite enhances As(III) oxidation in the presence of Fe(II) under oxic conditions and increases with increasing Cu content. Conversely, Zn incorporation leads to the opposite trend. The As(III) oxidation induced by surface-bound Fe(II) is positively related to the Fe(II) content and is favorable under acidic conditions. Reactive oxygen species (ROS), such as superoxide (·O 2− ) and H 2 O 2 , predominantly contribute to As(III) oxidation as a result of 1-electron transfer from bound Fe(II) to surface O 2 on hematite and radical propagation. Electrochemical analysis demonstrates that Cu incorporation significantly lower the oxidation potential of Fe(II) on hematite, whereas Zn led to a higher reaction potential for Fe(II) oxidation. Subsequently, distinct surface reactivities of hematite for the activation of O 2 to form ROS by surface-bound Fe(II) are evidenced by metal incorporation. Our study provides a new understanding of the changes in the surface chemistry of iron oxyhydroxides because of incorporating metals (Zn and Cu), and therefore impact the biogeochemical processes of pollutants in soils and subsurface environments.
研究领域:
环境科学
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土壤化学
·
地球化学
✓ 已验证
DOI
高影响因子
Journal of Water Process Engineering
·
2022
·
IF 7.34
Longwei Yin,Longjie Liu,Shen Lin,Gary Owens,Zuliang Chen
Arsenic (As) is a contaminant of global concern due to its negative impact on environmental systems, where As occurs mainly as two inorganic species, arsenite (As(III)) and arsenate (As(V)). Thus the simultaneously removal of both As(III) and As(V) from groundwater is a challenging issue. In this paper, zero-valent iron nanoparticles ( n ZVI) with high surface-active sites were used to simultaneously remove both As(III) and As(V) species from groundwater with removal efficiencies >99.9% for an initial concentration 100 μg L −1 . Ion chromatography atomic fluorescence (IC-AFS) analysis indicated that during removal As(III) was oxidized to As(V), while X-ray photoelectron spectroscopy (XPS) showed that the As species were adsorbed on to the surface of n ZVI by a complexation reaction. Furthermore, thermodynamic studies of the adsorption process indicated that adsorption was a spontaneous and endothermic chemisorption process. Finally, practical removal of both As species by n ZVI from real groundwaters was demonstrated with removal efficiencies of 99.9 and 70.9% for As(V) and As(III), respectively. The presence of other coexisting ions affected the removal efficiency, with phosphate and carbonate decreasing the removal efficiencies of both As(III) and As(V) due competition with active binding sites on the surface of n ZVI. Overall, this work demonstrated that n ZVI was a promising adsorbent for the practical removal of inorganic As species from complex environmental matrices such as groundwater.
研究领域:
环境科学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2023
·
IF 8.6
Wenlan Ji,Weiwei Li,Tian C. Zhang,Yuan Wang,Shaojun Yuan
Arsenic-containing water needs to be purified to reduce the global hazards of arsenic to human health and ecosystems. Herein, successive electrodeposition of SnO 2 and RuO 2 nanoparticles on the TiO 2 nanotube arrays (TNTAs) was performed to synthesize dimensionally stable TNTAs/SnO 2 /RuO 2 anodes for highly efficient electrocatalytic oxidation of As(III) in aqueous solution. Such a TNTAs/SnO 2 /RuO 2 anode possessed fast charge transfer, higher oxygen evolution potential (OEP), larger electrocatalytic active area, and excellent stability, and delivered effectively electrocatalytic oxidation As(III), of which 10 mg/L of As(III) was completely oxidized into As(Ⅴ) with lower toxicity within 20 min owing to the synergistic effect of RuO 2 and SnO 2 . Impressively, the optimized TNTAs/SnO 2 /RuO 2 -10 anode presented an excellent electrochemical stability and longer service lifetime, and its oxidation conversion efficiency of As(III) still could be maintained to be 98% as well as its kinetic reaction constant decreased by only 0.03 even after 11 recycled usage, which was ascribed to the intensified interaction between RuO 2 and TNTAs/SnO 2 . The excellence of the innovative anode was also evidenced through its strong anti-interference ability to coexisting ions and the elucidation of the associated oxidation reaction mechanism of As(III) on the surface of the anode by electron spin resonance and radical scavenger tests. This novel electrode integrates high electrocatalytic activity, high electron transport and high stability, ensures the long-term stable use of the electrode, while realizes efficient and rapid electrocatalytic oxidation of As(III) in aquatic environments. This work provides new ideas for further improving the catalytic performance and stability of dimensionally-stable anode materials.
研究领域:
环境科学
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材料科学
✓ 已验证
产品关联
DOI
高影响因子
APPLIED SURFACE SCIENCE
·
2022
·
IF 7.392
Zhao Li,Lei Wu,Min Chen,Qiwu Zhang,Shujuan Dai,Tonglin Zhao
Bismuth oxyiodide is one of the bismuth-based semiconductors which exhibits narrow band gaps and excellent visible light response, however modification strategies are usually desired for improving its photocatalytic reactivity. In this context, introduction of valuable components into the interlayer of BiOI is expected to work, considering its typical layered structure. In this case, mechanochemical synthesis of BiOI, with simultaneous introduction of lanthanum into its interlayer to form Bi 1-x La x OI, was conducted for the first time, and arsenic (As(III)) was selected to evaluate the photocatalytic reactivity, demonstrating excellent reaction efficiency for arsenic oxidation under a mild condition. Characterizations confirmed the incorporation of La and the presented well crystalline structure of Bi 1-x La x OI, and revealed its better visible light absorption capacity than raw BiOI. Besides the excellent electronic conductivity of Bi 0.9 La 0.1 OI, photogenerated holes (h + ) and superoxide radical species (· O 2 - ) were characterized by electron spin resonance (ESR) test, to act as predominant reactive groups during the photo-induced oxidation reaction. These findings provided a novel concept for the interlayer decoration of BiOI, and offered an alternative approach to develop its potential application for the removal of hazardous arsenic pollutants.
研究领域:
环境科学
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材料科学
✓ 已验证
DOI
高影响因子
SCIENCE OF THE TOTAL ENVIRONMENT
·
2022
·
IF 10.753
Changyin Zhu,Chenyan Xue,Mingquan Huang,Fengxiao Zhu,Guodong Fang,Dixiang Wang,Shaochong Liu,Ning Chen,Song Wu,Dongmei Zhou
Activated carbon (AC) is widely used in pollutant removal , due to its adsorption capacity, conductivity and catalytic performance. However, few studies focus on the redox activity of AC and its role in pollutant transformation. In this study, we found that AC could efficiently mediate the oxidation of As(III) and the process of As(III) oxidation was pH and oxygen concentration dependent. In general, the presence of O 2 promoted As(III) oxidation at pH 3.0–9.5. Acidic and alkaline conditions favored As(III) oxidation regardless of whether there was oxygen, but the mechanisms involved were quite different when there was oxygen. At pH 3.0, reactive species (H 2 O 2 and ·OH) were generated and accounted for As(III) oxidation; at pH 9.5, As(III) was directly oxidized by O 2 (electron transfer from As(III) to O 2 mediated by carbon matrix) under aerobic conditions . Pre-oxidation and cyclic experiments results indicated the ability of AC to oxidize As(III) at pH 9.5 was sustainable and recyclable. This study provided a new insight in pollutant oxidation by AC in the environment.
研究领域:
环境科学
·
化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
WATER RESEARCH
·
2023
·
IF 12.8
Chaoyun Ying,Chang Liu,Feng Zhang,Lirong Zheng,Xiaoming Wang,Hui Yin,Wenfeng Tan,Xionghan Feng,Bruno Lanson
Manganese (Mn) oxides are extensively used to oxidize As(III) present in ground, drinking, and waste waters to the less toxic and more easily removable As(V). The common presence of multiple other cations in natural waters, and more especially of redox-sensitive ones such as Fe 2+ , may however significantly hamper As(III) oxidation and its subsequent removal. The present work investigates experimentally the influence of Mn(III) chelating agents on As(III) oxidation process in such environmentally relevant complex systems. Specifically, the influence of sodium pyrophosphate (PP), an efficient Mn(III) chelating agent, on As(III) oxidation by birnessite in the presence of Fe(II) was investigated using batch experiments at circum-neutral pH. In the absence of PP, competitive oxidation of Fe(II) and As(III) leads to Mn oxide surface passivation by Fe(III) and Mn(II/III) (oxyhydr)oxides, thus inhibiting As(III) oxidation. Addition of PP to the system highly enhances As(III) oxidation by birnessite even in the presence of Fe(II). PP presence prevents passivation of Mn oxide surfaces keeping As and Fe species in solution while lower valence Mn species are released to solution. In addition, reactive oxygen species (ROS), tentatively identified as hydroxyl radicals (•OH), are generated under aerobic conditions through oxygen activation by Fe(II)–PP complexes, enhancing As(III) oxidation further. The positive influence of Mn(III) chelating agents on As(III) oxidation most likely not only depend on their affinity for Mn(III) but also on their ability to promote formation of these active radical species. Finally, removal of As(V) through sorption to Fe (oxyhydr)oxides is efficient even in the presence of significant concentrations of PP, and addition of such Mn(III) chelating agents thus appears as an efficient way to enhance the oxidizing activity of birnessite in large-scale treatment for arsenic detoxification of groundwaters.
研究领域:
环境科学
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化学
·
水处理工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Molecular Catalysis
·
2021
·
IF 5.062
Jingyu Zhao,Cong Wang,Yaru Li,Congmei Chen,Ping Na
This study revealed the mechanism of the photocatalytic oxidation of As(III) by phosphotungstic acid (PTA) via experiments and density functional theory (DFT) simulations. All the experimental results were highly consistent with the simulated data. The results showed that hydroxyl radical ( OH)was the main reactive species for the photocatalytic oxidation of As(III) by PTA. Interestingly, when 2-propanol was added to the system, the main reactive species was converted to peroxide species (-OOH). The effect of the O 2 , H-sites, radicals, and light irradiation time were studied in this research and a 5 steps -OOH mechanism of oxidation of As(III) was first proposed and proved. This mechanism included the adsorption of O 2 on H-sites of the catalyst surface; the formation of the peroxide species -OOH; the -OOH dissociated from catalyst surface and reacted with As(III) to form HOO-As(III) compound; the transformation of the HOO-As(III) to As(V); and the regeneration of the catalyst. What represented in this study should provide a rational theoretical support for oxidation of As(III) to As(V).
研究领域:
环境科学
·
化学
✓ 已验证
DOI
高影响因子
Journal of Environmental Chemical Engineering
·
2022
·
IF 7.968
Jinglin Yin,Junhui Yang,Yanmei Li,Ziyang Xiang,Ting Yang,Jing Wang,Tao Xu,Qiong Wang,Wenlei Wang
This study investigated the Fenton-like oxidation of As(III) by three types of iron oxides in oxalate systems. The effects of pH, oxalate concentration and atmosphere on the oxidation of As(III) by iron oxide photocatalyst were studied. Firstly, hydrothermal carbon (HTC) was used as the carrier to load three kinds of iron oxides to prepare new composite materials, including α–FeOOH, α Fe 2 O 3 and Fe 3 O 4 , which can solve the dispersion problem of iron oxide by using a large number of rich functional groups on the HTC surface. The experiment results showed that under the conditions of O 2 , pH = 5.0 and oxalate concentration of 0.5 mmol·L 1 , As(III) was completely oxidized by α–FeOOH and α–Fe 2 O 3 at 15 min and 20 min, respectively. Density functional theory (DFT) was used to study the surface adsorption energy of iron oxide and oxalate. The calculated results showed that the order of adsorption energy of three iron oxides for the oxalate is α FeOOH > α Fe 2 O 3 > Fe 3 O 4 . Fe III (C 2 O 4 ) + , a mononuclear bidentate iron oxalate chelate with the strongest photosensitivity , was constructed in the Fe-Oxalate system containing only Fe(III), resulting in the photocatalytic efficiency of α–FeOOH and α Fe 2 O 3 was superior to that of Fe 3 O 4 . These findings contribute to arsenic remediation of water bodies by using iron materials and oxalate in the natural environment.
研究领域:
环境科学
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化学
✓ 已验证
DOI
高影响因子
GEOCHIMICA ET COSMOCHIMICA ACTA
·
2012
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IF 4.259
Hui Yin,Wenfeng Tan,Lirong Zheng,Haojie Cui,Guohong Qiu,Fan Liu,Xionghan Feng
Hexagonal birnessite is the most ubiquitous manganese oxide in geological environments. It is often highly enriched in trace metal ions such as Ni and plays an important role in metal(loids) geochemistry . Nanostructured birnessites containing different amounts of Ni were synthesized by addition of Ni 2+ to initial reactants. Powder X-ray diffraction (XRD), element analysis, field emission scanning electron microscopy (FE-SEM), X-ray photoelectron spectroscopy (XPS), thermogravimetric analysis (TGA), X-ray absorption spectroscopy (XAS) and isothermal adsorption and oxidation of metal(loids) were carried out to investigate the effects of Ni doping on the substructure and physicochemical properties of birnessite, and Ni crystal chemistry in birnessite. These Ni-rich birnessites have Ni contents as high as 2.99% (Ni5) and 6.08% (Ni10) in weight. EXAFS results show that Ni5 has 23.7% of the total Ni (0.71 wt.%) and Ni10 has 34.5% of the total Ni (2.10 wt.%) in Mn octahedral layer with the remaining Ni located at vacancies and edge sites. The Ni-rich birnessites have weaker crystallinity and thermal stability, fewer layers stacked along the c axis, ∼1.5–2.7 times larger surfaces areas, and a higher Mn average oxidation numbers (AONs) compared to the birnessite without Ni. Additionally, the doping of Ni during birnessite crystallization enhances the formation of vacancies in the layer; however, adsorption capacities for Pb 2+ and Zn 2+ by these Ni-rich birnessites are reduced, mainly because of vacancies and edge sites occupation by a large amount of Ni. The Ni-rich birnessites exhibit much higher oxidation capability and can completely oxidize As(III) in solution at rapid initial reaction rates under the experimental condition. The results indicate that incorporation of Ni into the natural birnessite in ferromanganese nodules may be achieved both by direct coprecipitation with Mn to build the layers and migration over time from adsorbed Ni on the surface into the layer structure. It is also implied that Ni doping in birnessite has great impact on the geochemical behaviors of heavy metals, either in adsorption or oxidation reactions.
研究领域:
地球化学
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环境科学
✓ 已验证
产品关联
DOI
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2024
·
IF 8.1
Siqi Wang,Jia Wang,Lingzhi He,Fang Luo,Zhuwei Liao,Yi Wu,Zhuo Liu,Yu He,Zhuqi Chen
Complete remediation of organoarsenics from environmental matrix hits the bottleneck, that is, the sluggish efficiency of oxidative degradation towards organoarsenics and unsatisfying immobilization performance towards generated inorganic arsenic. Herein, we establish a biochar accelerated Fenton (BA-Fenton) process to decontaminate water from roxarsone (ROX). In comparison with Fe 2+ /H 2 O 2 process (10 μΜ/0.2 mM), the incorporation of 0.5 g L -1 biochar promoted ROX degradation from 48.2% to 98.2% and total arsenic elimination from 67.6% to 97.3%, respectively. In BA-Fenton process, •OH as the dominant reactive oxygen species (ROS), exhibited a cumulative concentration of 0.42 mM, three times higher than that in classical Fenton process. Crucially, the presence of biochar in Fenton process significantly enhanced the stability of arsenic-iron sludge, whereas the secondary leaching of total arsenic decreased from 433.8 μg-As L -1 to 13.9 μg-As L -1 , meeting the prescribed environmental quality standards for surface water in China (50 μg-As L -1 , GB 3838-2002). Mechanistic studies unveiled ROX remediation mechanism by BA-Fenton process, highlighting the dual functionality of biochar. On one hand, biochar efficiently reduced Fe 3+ to Fe 2+ with a rate constant of 0.225 min -1 , overcoming the rate-determining step of classical Fenton process for •OH production, consequently promoting the transformation of ROX to As(V). On the other hand, molecular spectroscopy analysis elucidated that in-situ formed As(V) was adsorbed by ferric hydroxides with the formation of arsenic-iron sludge. Subsequently, biochar immobilized arsenic-iron sludge through hydrogen bonds, electrostatic attraction and surface complexation. Furthermore, real water studies demonstrated the effective remediation of organoarsenics by BA-Fenton process in tap water, lake water and chicken manure leachate. This “Two Birds with One Stone” strategy with low-cost, environmental-friendly and sustainable biochar holds great promise for the ultimate disposal of industrial wastewater containing organoarsenics.
研究领域:
环境科学
·
污染控制
·
水处理技术
✓ 已验证
产品关联
DOI
高影响因子
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
·
2020
·Vol. 22
·期 22
·12456-12464
·
IF 3.43
Xiang-Ming Wang,Song-Hai Wu,Hai-Tao Ren,Peng-Yue Zhu,Cong Wang,Yong Liu,Shi-Wei Sun,Xiao-Cong Zhang,Yi-Ying Lin,Zi-He Meng,Shao-Yi Jia,Xu Han
Bi2+xWO6 is a cost-effective and environmentally friendly photocatalyst that shows high reactivity in the oxidation of various contaminants under visible light. However, under alkaline conditions, the reactive oxidative species in the Bi2+xWO6 system are still not clear yet. In this study, it is observed that the oxidation rates of As(III) increase with increasing pH values in the Bi2.15WO6 system. Photoluminescence and the Mott–Schottky analyses confirm that OH− promotes the separation and transfer of photogenerated electron–hole pairs over Bi2.15WO6, thus facilitating the oxidation of As(III). Electron spin resonance spectra analysis and quenching experiments rule out contributions of •OH, O2˙−, 1O2 and superoxo species to As(III) oxidation and indicate that surface –OOH and/or H2O2 are indeed the predominant species under alkaline conditions. The improved production of H2O2 by H-donors such as glucose and phenol, as well as the UV-vis diffuse reflectance and Raman analyses, further confirms the formation of surface –OOH on Bi2.15WO6 under alkaline conditions. In the dark, the significant higher oxidation rate of As(III) by H2O2–Bi2.15WO6 than that by H2O2 alone reveals that surface −OOH, instead of H2O2, plays an important role in As(III) oxidation. This study enriches our understanding of the diversity of reactive oxygen species (ROS) in the Bi2.15WO6 system and gives new insight into the mechanism involved in the oxidation of As(III) under alkaline conditions.
研究领域:
环境科学
·
光催化
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材料科学
✓ 已验证
DOI
PubMed
高影响因子
APPLIED SURFACE SCIENCE
·
2023
·
IF 6.7
Wenlan Ji,Yijiang He,Tian C. Zhang,Yuan Wang,Shaojun Yuan
The novel non-noble metal anodes of Ni-based (Co 2+ , Fe 2+ , and Mn 2+) layered double hydroxides (Ni-based LDH) were uniformly anchored on the carbon cloth (CC) surface (denoted as Ni-based LDHs/CC) by a simple, rapid and universal electrodeposition approach. The low-cost NiCo-LDH/CC anodes not only possessed superior conductivity and more exposed reactive sites, but also delivered promising electrocatalytic oxidation ability. Notably, the electrocatalytic oxidation efficiency of the obtained NiCo-LDH/CC and NiMn-LDH/CC anodes were positively correlated with the deposition amount of NiCo-LDH and NiMn-LDH, wherein NiCo-LDH-180s/CC anode delivered a significant enhancement in electrocatalytic oxidation efficiency of As(III), over 4.7 times higher than that of pure CC. Impressively, the NiCo-LDH-180s/CC anode exhibited larger electrochemical active areas and outstanding electrocatalytic activity, and can achieve nearly 100% conversion efficiency within 20 min at a current density of 6 mA/cm 2 . In particular, the developed anode is also distinguished by its adaptability to different pH values and its strong immunity to coexisting ions, which is expected to be widely applied in various As(III)-contaminated environments. Electron spin resonance spectra fully validated the formation of free radicals (•OH and •O 2 − ) with strong oxidative properties, and was employed to further investigate the associated reaction mechanism in combination with quenching experiments. This work potentially offers an in-depth perspective of electrocatalytic technology for the decontamination of highly toxic As(III) wastewater through cost-effective non-noble metal anodes and broadens the scope of electrocatalysts.
研究领域:
环境科学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）