WATER RESEARCH
·
2021
·
IF 11.236
Shuai Wang,Kai Zheng,Heping Li,Xiaonan Feng,Luying Wang,Qingyou Liu
Arsenopyrite is a common metal sulfide mineral and weathers readily in the open environment, releases As, and pollutes the surrounding environment. Humic acid (HA) is ubiquitous in soils, sediments and waters, and contains various functional groups and complex with arsenic, iron and other metal ions that affect the weathering behavior of arsenopyrite. Because As, iron, and HA are redox-active compounds, electrochemical techniques, including polarization curves, electrochemical impedance spectroscopy (EIS), and cyclic voltammetry (CV), were used to fundamentally investigate the weathering process and mechanism of arsenopyrite over a wide range of environmental relevant conditions. Polarization curves showed higher HA concentrations (0-1000 mg•L −1 ), higher temperatures (5-35°C) or acidities (pH 1.0-7.0) promoted arsenopyrite weathering; there was a linear relationship between the corrosion current density ( i corr ), temperature (T) and acidity (pH): i corr = -3691.2/ T + 13.942 and i corr = -0.2445pH + 2.2125, respectively. Arsenopyrite weathering readily occurred in the presence of HA as confirmed by its activation energy of 24.1 kJ•mol −1 , and EIS measurements confirmed that the kinetics were controlled by surface reaction as confirmed by decreased double layer resistance. CV and surface characterization (FTIR and XPS) showed that arsenopyrite initially oxidized to S 0 , As(III) and Fe 2+ , then S 0 and Fe 2+ were ultimately converted into SO 4 2− and Fe 3+ , while As(III) oxidized to As(V). Furthermore, the carboxyl (–COOH) and phenolic (–OH) of HA could bind with As(III)/(V) and Fe 3+ via a ligand exchange mechanism forming As(III)/(V)-HA and As(III)/(V)-Fe-HA complexes that hinders the formation of FeAsO 4 and decreases the bioavailability of As. Findings gained from this study are valuable for the understanding of the fate and transport of As in acidic conditions, and have powerful implications for the remediation and management of As-bearing sites affected by mining activities.
研究领域:
环境科学
·
地球化学
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DOI
PubMed
高影响因子
PLoS One
·
2014
·Vol. 9
·期 6
·e100704
·
IF 3.534
Shams Ali Baig,TianTian Sheng,Chen Sun,XiaoQin Xue,LiSha Tan,XinHua Xu
The presence of elevated concentration of arsenic in water sources is considered to be health hazard globally. Calcination process is known to change the surface efficacy of the adsorbent. In current study, five adsorbent composites: uncalcined and calcined Fe 3 O 4 -HBC prepared at different temperatures (400°C and 1000°C) and environment (air and nitrogen) were investigated for the adsorptive removal of As(V) and As(III) from aqueous solutions determining the influence of solution's pH, contact time, temperature, arsenic concentration and phosphate anions. Characterizations from FTIR, XRD, HT-XRD, BET and SEM analyses revealed that the Fe 3 O 4 -HBC composite at higher calcination temperature under nitrogen formed a new product (fayalite, Fe 2 SiO 4 ) via phase transformation. In aqueous medium, ligand exchange between arsenic and the effective sorbent site ( = FeOOH) was established from the release of hydroxyl group. Langmuir model suggested data of the five adsorbent composites follow the order: Fe 3 O 4 -HBC-1000°C(N 2 )>Fe 3 O 4 -HBC (uncalcined)>Fe 3 O 4 -HBC-400°C(N 2 )>Fe 3 O 4 -HBC-400°C(air)>Fe 3 O 4 -HBC-1000°C(air) and the maximum As(V) and As(III) adsorption capacities were found to be about 3.35 mg g −1 and 3.07 mg g −1 , respectively. The adsorption of As(V) and As(III) remained stable in a wider pH range (4–10) using Fe 3 O 4 -HBC-1000°C(N 2 ). Additionally, adsorption data fitted well in pseudo-second-order ( R 2 >0.99) rather than pseudo-first-order kinetics model. The adsorption of As(V) and As(III) onto adsorbent composites increase with increase in temperatures indicating that it is an endothermic process. Phosphate concentration (0.0l mM or higher) strongly inhibited As(V) and As(III) removal through the mechanism of competitive adsorption. This study suggests that the selective calcination process could be useful to improve the adsorbent efficiency for enhanced arsenic removal from contaminated water.
研究领域:
环境科学
·
材料科学
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DOI
PubMed
高影响因子
ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY
·
2020
·
IF 4.872
Rongtao Lyu,Zhixiang Gao,Deliang Li,Zhaoguang Yang,Ting Zhang
The bioaccessibility of total arsenic (tAs) and arsenic species in Bellamya aeruginosa collected from Xiangjiang River was evaluated using an in vitro digestion model, to assess the potential health risks to local residents. The tAs concentrations in gastropod samples ranged from 1.98 to 6.33 mg kg −1 (mean 3.79 ± 1.60 mg kg −1 ). Five arsenic species including arsenite [As(III)], arsenate [As(V)], dimethylarsinic acid (DMA), arsenobetaine (AsB), and arsenocholine (AsC) were detected. Inorganic arsenic (iAs) concentrations, which were about a half of organic arsenic (oAs), were higher than the maximum permissible limit (≤0.50 mg kg −1 in aquatic products). Bioaccessible concentrations of tAs in digestive juices were found to be decreased in the order: intestinal phase > gastric phase > salivary phase. As(III) and AsC were the predominant species, but AsB was not detectable in all digestive juices. Bioaccessible iAs concentrations, which were close to the level of bioaccessible oAs, were not significantly different among three digestive juices, but also above 0.50 mg kg −1 . Accordingly, bioaccessibility of tAs was highest in intestinal phase (48%), then in gastric phase (40%), and lowest in salivary phase (33%). Bioaccessibility of As(III) was close to 100%, and bioaccessibility of iAs was much higher than that of oAs. The mean values of target hazard quotient (THQ) and bioaccessible THQ were 0.80 and 0.70, respectively. The probability of experiencing non-carcinogenic effects was reduced to 18% down from 22% as considering iAs bioaccessibility. The mean values of carcinogenic risk (CR) and bioaccessible CR were higher than the acceptable value (1 × 10 −4 ). Gastropod consumption from sampling sites may cause a potential carcinogenic risk.
研究领域:
环境科学
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毒理学
·
公共卫生
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DOI
PubMed
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2019
·
IF 8.355
Na Chen,Yichao Wan,Guangming Zhan,Xiaobing Wang,Meiqi Li,Lizhi Zhang
Solar light driven organoarsenicals degradation and simultaneous inorganic arsenic immobilization with naturally abundant hematite is very promising for organoarsenicals remediation, but suffers from the fast electron-hole charge recombination of hematite. Herein, we report that oxalate, widely existed in soil and water environments, can greatly enhance the photocatalytic molecular oxygen activation of hematite to degrade a typical organoarsenical roxarsone and immobilize the resulted inorganic arsenic. It was found that oxalate could chelate with surface Fe(III) of hematite to generate plenty of •OH via a surface Fe(III)/Fe(II) cycle mediated oxygen molecular activation process under a simulated solar light, and thus induced 85.1% of roxarsone transformation into inorganic arsenic species, mainly As(V), within 6 h. The generated As(V) could be further adsorbed on hematite surface with prolonging the reaction time to 24 h in dark, avoiding secondary pollution. More importantly, hematite was reusable for the simulated solar light driven roxarsone degradation and As(V) immobilization in the presence of oxalate. This study offers a green and effective strategy for organoarsenicals remediation, and also sheds light on the environmental effects of iron oxides and oxalate.
研究领域:
环境科学
·
光化学
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DOI
高影响因子
CHEMOSPHERE
·
2019
·
IF 5.108
Zhigang Wei,Yangfei Fang,Zhenrui Wang,Yue Liu,Yang Wu,Kai Liang,Jiahong Yan,Zhanchang Pan,Guanghui Hu
TiO 2 is one of the most cheap materials which can both adsorb arsenic and oxidize arsenite [As(III)] to arsenate [As(V)]. In this study, anatase TiO 2 crystals with different main facets such as {101}, {001} and {100} are synthesized and used to investigate arsenic adsorption kinetics, adsorption isotherms, photocatalytic oxidation (PCO) process and the pH effects. The adsorption kinetics of arsenic on TiO 2 crystals can be described by the pseudo second-order kinetic model. For the adsorption isotherms, the Langmuir model is better than the Freundlich model for arsenic on these TiO 2 crystals. For the PCO process, the rate of As(III) oxidation can be denoted by the pseudo first-order kinetic model. It should be noted that at neutral condition the adsorption and PCO rates of the three kinds of TiO 2 crystals follow the order of {101} > {001} > {100}. The pH effect is above all important for both the arsenic adsorption and its PCO. The highest PCO speed appears at high pH values such as at pH 11 or 12.
研究领域:
环境科学
·
材料科学
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DOI
PubMed
高影响因子
Journal of Cleaner Production
·
2021
·
IF 9.297
Yu Yong,Wang Hua,Hu Jianhang,Zhong Dapeng
Tin-bearing middling, a hazardous solid waste produced during beneficiation of tin deposits and tin-bearing tailings, presents a serious environmental pollution risk due to high levels of As. This paper aims to explore an environmentally friendly technology to reduce toxic substances and prepare a high value-added bronze material from tin-bearing middling. The co-process for tin-bearing middling, anthracite , and copper is first proposed at 1073–1123 K. Variables like temperature, amount of added anthracite, and holding time were optimized. Those results showed that 95.56% Sn and 92.79% As were recovered; levels of Fe in the residue reached 73.52 wt%. During roasting, SnO 2 in the tin-bearing middling was initially transformed into SnO(g), then into an Fe–Sn spinel (Fe 3-x Sn x O 4 ) and Ca 2 SnO 4 , and finally a Cu–Sn alloy. Generation of the Fe–Sn spinel came primarily from substitution of Fe 2+ by Sn 2+ , but small amounts of Sn 4+ replaced Fe 3+ in Fe 3 O 4 . Meanwhile, FeAsS and FeAsO 4 were initially transformed into As 4 (g) and then solidified as a Cu–As alloy. Interestingly, the residual As existed as Fe–As alloy, but As leaching levels did not exceed 0.02 mg/L. After initial treatment, the Cu alloy can be prepared for bronze. Meanwhile, subsequent volatilization and solidification of As resulted in a significant reduction of arsenic-bearing waste that minimizes environmental risk.
研究领域:
冶金工程
·
环境科学
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DOI
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
·
化学
·
水处理工程
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DOI
PubMed
高影响因子
ECOTOXICOLOGY
·
2017
·Vol. 26
·期 2
·202-210
·
IF 1.951
Ding Tengda,Zhang Jianying,Ni Wanmin,Li Juying
The toxicity and bioavailability of single arsenic species have been widely investigated, however, the biological effects of mixed arsenic species co-existing in natural waters still remain unknown. The objective of this work was to discern the adverse effects of combined arsenite (As(III)) and dimethylarsenic acid (DMA) on diatom Nitzschia palea . The combined ecotoxicity of As(III) and DMA on N. palea was observed to be time-dependent and showed dose-effect relation. The toxicity of DMA and As(III) mixture was higher than individual DMA or As(III) when the As(III) concentration was in the range of 0.085–0.316 mg L −1 . As the As(III) concentration increased from 0.487 to 0.858 mg L −1 , the antagonistic effect was found, which could be due to the higher thiols contents in the thiol-containing proteins (e.g., frustulins, silaffins and other glycoproteins). The content of malondialdehyde (MDA) in the treatment of mixed arsenic species was found to be at the same level compared to the As-free control after 72 h of exposure, indicating that the co-toxicity of As(III) and DMA on diatom frustules was not significant. Furthermore, the increase of frustule formation rate in the mixture of EC 50 As(III)-EC 10 DMA at 72 h exposure time indicated that the damaged diatom cell walls was likely repaired gradually. The results from this study suggested that the effects of co-existed arsenic species were concentration-specific and should be considered in the risk assessment of arsenic and development of water quality criteria for the protection of aquatic ecosystems.
研究领域:
环境生物学
·
生态毒理学
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产品关联
DOI
PubMed
高影响因子
CHEMOSPHERE
·
2022
·
IF 8.943
Yongkui Li,Xianjin Qi,Guohua Li,Xiaoxu Duan,Nina Yang
High-arsenic wastewater has long been considered a major threat to ecological balance and human health because of its strong toxicity and high mobility. Herein, an environmentally friendly process was proposed for As removal and fixation in the form of As-stabilized mineral, using Lead–Zinc smelting (LZS) slag as the in situ Fe donor, neutralizer, and crystal seed. The slag was dissolved in the wastewater and released Fe and Ca ions, while simultaneously increasing the pH value of the solution to help scorodite synthesis. The dissolved Ca 2+ ion preferentially reacted with SO 4 2− ion in the form of CaSO 4 ·2H 2 O precipitate as in situ “seeds” for As precipitation. The dissolved Fe(II) and As(III) ions were oxidized to Fe(III) and As(V) ions by H 2 O 2 , and later reacted with each other to generated amorphous ferric arsenate on the surface of CaSO 4 ·2H 2 O, and then evolved into scorodite crystals with high stability. With a Fe/As molar ratio of 2, a reaction temperature of 90 °C, and a reaction time of 12 h, 98.42% of As was effectively precipitated from the wastewater with an initial As concentration of 7530.00 mg/L. Moreover, the leached As concentration of the As-bearing precipitate in the TCLP test was 3.46 mg/L. The concentration of the residual As and heavy metals ions in the final filtrate was lower than local wastewater discharge standards, successfully realizing the treatment of smelting wastewater. In summary, a prospective process successfully shows a great potential for co-treatment of LZS wastewater and slag, which could advance the large-scale disposal of LZS plants.
研究领域:
环境科学
·
化学工程
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产品关联
DOI
PubMed
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2025
·
IF 13.2
Kang Feng,Jing Cao,Dandan Wu,Jianan Li,Qi Zuo,Shaojun Bai
This study investigates the effect of sodium percarbonate (SPC) as an eco-friendly oxidant on the flotation separation of bornite and arsenopyrite. Micro-flotation tests demonstrated that SPC significantly suppressed arsenopyrite floatability while maintaining bornite floatability. In artificial mixed-ore tests conducted at pH 10 with 500 mg/L SPC and 5 × 10 −5 mol/L sodium butyl xanthate (NaBX), bornite recovery reached 87.93 %, whereas arsenopyrite recovery was only 14.51 %, which resulted in a substantial recovery difference of 73.42 %. Surface analysis via contact angle measurements, scanning electron microscopy-energy dispersive X-ray spectroscopy (SEM-EDS), atomic force microscopy (AFM), localized electrochemical impedance spectroscopy (LEIS), X-ray photoelectron spectroscopy (XPS), and time-of-flight secondary ion mass spectrometry (ToF-SIMS) revealed that SPC treatment enhanced the hydrophilicity of arsenopyrite compared with that of bornite. LEIS, XPS, and ToF-SIMS confirmed the formation of hydrophilic oxides such as FeAsO 4 , H 3 AsO 3 , Fe(OH) 3 , and Fe 2 (SO 4 ) 3 on arsenopyrite surfaces, which ultimately reduced floatability. In contrast, bornite surfaces exhibited only slight oxidation, with minimal increases in Cu(OH) 2 , Fe(OH) 3 , and Fe 2 (SO 4 ) 3 which only resulted in a modest decrease in floatability. SEM–EDS and AFM analyses revealed significant changes in the surface morphology of arsenopyrite after SPC treatment, with increased oxygen content and surface roughness, which indicated the formation of an oxide layer. In contrast, bornite surfaces remained relatively smooth, with only a slight increase in oxygen content. This study provides valuable theoretical reference into the use of eco-friendly depressants for copper–arsenic mineral separation.
研究领域:
矿物加工工程
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
WATER RESEARCH
·
2024
·
IF 11.4
Shiqi Tian,Yuwei Ma,Yuanyuan Xu,Yingzi Lin,Jun Ma,Gang Wen
Dissolved Mn(III), as a potent one-electron transfer oxidant, is ubiquitous in natural waters and sediments and actively involved in the transformation of organics in biogeochemical processes and water treatment. However, the important role of Mn(III) has long been overlooked because of its short life. This study was the first to investigate the performance of Mn(III) in organoarsenic transformation and to highlight the environmental implications. Both homogeneous and heterogeneous Mn(III)-based systems were effective to remove p -arsanilic acid ( p -ASA, 15 μ M) with degradation efficiency approaching 40.4 %–98.3 %. Two degradation pathways of p -ASA were proposed, in which As-C bond and amino group were vulnerable sites to Mn(III) attack, leading to the formation of more toxic arsenate (As(V)) and nitarsone. Through transforming organoarsenic to inorganic arsenic species, the removal efficiency of total arsenic and dissolved organics were enhanced to 65.1 %–95.5 % and 16.6 %–36.6 %, respectively, by post-treatment of coagulation or adsorption, accompanied with significant reduction of cytotoxicity and environmental risks. Particularly, polymeric ferric sulfate and granular activated alumina showed superior performance in the total As removal. Moreover, oxidation efficiency of Mn(III) was hardly affected by common cations and anions (e.g., Ca 2+ , Mg 2+ , NH 4 + , NO 3 ˉ, SO 4 ˉ), halide ions (e.g., Clˉ, Brˉ) and natural organic matter, showing high robustness for organoarsenic removal under complicated water matrices. Overall, this study shed light on the significance of Mn(III) to the fate of organoarsenics in manganese-rich environments, and demonstrated the promising potential of Mn(III)-based strategies to achieve targeted decontamination in water/wastewater purification.
研究领域:
环境科学
·
水处理工程
·
毒理学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ENVIRONMENTAL POLLUTION
·
2022
·
IF 9.988
Meng Zhou,Zishu Liu,Baofeng Zhang,Jiawen Yang,Baolan Hu
Microorganisms are essential for modifying arsenic morphology, mobility, and toxicity. Still, knowledge of the microorganisms responsible for arsenic metabolism in specific arsenic-contaminated fields, such as metallurgical plants is limited. We sampled on-field soils from three depths at 70 day intervals to explore the distribution and transformation of arsenic in the soil. Arsenic-metabolizing microorganisms were identified from the mapped gene sequences. Arsenic metabolism pathways were constructed with metagenomics and AsChip analysis (a high-throughput qPCR chip for arsenic metabolism genes). It has been shown in the result that 350 genera of arsenic-metabolizing microorganisms carrying 17 arsenic metabolism genes in field soils were identified, as relevant to arsenic reduction, arsenic methylation , arsenic respiration, and arsenic oxidation, respectively. Arsenic reduction genes were the only genes shared by the 10 high-ranking arsenic-metabolizing microorganisms. Arsenic reduction genes ( arsABCDRT and acr3 ) accounted for 73.47%–78.11% of all arsenic metabolism genes. Such genes dominated arsenic metabolism, mediating the reduction of 14.11%–19.86% of As(V) to As(III) in 0–100 cm soils. Arsenic reduction disrupts microbial energy metabolism, DNA replication and repair and membrane transport. Arsenic reduction led to a significant decrease in the abundance of 17 arsenic metabolism genes ( p < 0.0001). The critical role of arsenic-reducing microorganisms in the migration and transformation of arsenic in metallurgical field soils, was emphasized with such results. These results were of pronounced significance for understanding the transformation behavior of arsenic and the precise regulation of arsenic in field soil.
研究领域:
环境科学
·
微生物学
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产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）