ELECTROPHORESIS
·
2020
·Vol. 42
·期 6
·719-724
·
IF 3.081
Evgeniya V. Polyakova,Olga V. Shuvaeva,Olga S. Koshcheeva,Yuliya E. Tyutereva,Ivan P. Pozdnyakov
Arsenic aromatic compounds including p-arsanylic acid (pASA) are still widely used in a number of countries as the feed additives in animal breeding resulting in its entering the environment. Under the influence of oxidizing agents or UV radiation, pASA undergoes transformations leading to generation of inorganic arsenic species that are more mobile and toxic than organic ones. On the one hand, an approach based on the treatment of contaminated waters by UV irradiation seems perspective for their detoxification, but the feasibility of this approach depends on the composition of the products forming as a result of photodegradation. In the present work, a CZE was applied for the study of the pASA degradation process during stationary (308 nm) photolysis in the presence of Fe(III)-oxalate complex. A developed assay allowed controlling the parent compounds and also As-containing products of pASA degradation, presented mainly by arsenate and arsenite ions. It was found that the main inorganic derivatives of the pASA photolytic conversions are presented by arsenate and arsenite ions whose ratio depends on the initial amount of pASA and reaction conditions.
研究领域:
环境科学
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分析化学
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DOI
PubMed
高影响因子
Materials
·
2022
·Vol. 15
·期 21
·7471
·
IF 3.748
Pan Chen,Yuxin Zhao,Jun Yao,Jianyu Zhu,Jian Cao
In situ treatment of acidic arsenic-containing wastewater from the non-ferrous metal smelting industry has been a great challenge for cleaner production in smelters. Scorodite and iron arsenate have been proved to be good arsenic-fixing minerals; thus, we used lead slag as an iron source to remove arsenic from wastewater by forming iron arsenate and scorodite. As the main contaminant in wastewater, As(III) was oxidized to As(V) by H2O2, which was further mineralized to low-crystalline iron arsenate by Fe(III) and Fe(II) released by lead slag (in situ generated). The calcium ions released from the dissolved lead slag combined with sulfate to form well-crystallized gypsum, which co-precipitated with iron arsenate and provided attachment sites for iron arsenate. In addition, a silicate colloid was generated from dissolved silicate minerals wrapped around the As-bearing precipitate particles, which reduced the arsenic-leaching toxicity. A 99.95% removal efficiency of arsenic with initial concentration of 6500 mg/L was reached when the solid–liquid ratio was 1:10 and after 12 h of reaction at room temperature. Moreover, the leaching toxicity of As-bearing precipitate was 3.36 mg/L (As) and 2.93 mg/L (Pb), lower than the leaching threshold (5 mg/L). This work can promote the joint treatment of slag and wastewater in smelters, which is conducive to the long-term development of resource utilization and clean production.Keywords:arsenic wastewater;lead slag;iron arsenate;scorodite
研究领域:
环境科学
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冶金工程
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DOI
PubMed
高影响因子
ENVIRONMENTAL SCIENCE & TECHNOLOGY
·
2016
·
IF 5.393
Xue Liu,Jing-Wei Fu,Dong-Xing Guan,Yue Cao,Jun Luo,Bala Rathinasabapathi,Yanshan Chen,Lena Q. Ma
Arsenic hyperaccumulator Pteris vittata (PV) is efficient in taking up As and nutrients from As-contaminated soils. We evaluated the mechanisms used by PV to mobilize As and Fe by examining the impacts of As and root exudates on FeAsO4 solubilization, and As and Fe uptake in four plants: As-hyperaccumulators PV and Pteris multifida (PM), nonhyperaccumulator Pteris ensiformis (PE), and angiosperm plant tomato (Solanum lycopersicum). Phytate and oxalate were dominant in fern plants (>93%), which were 50–83, 15–42, and 0–32 mg kg–1 phytate and 10–15, 7–26, and 4–12 mg kg–1 oxalate for PV, PM, and PE respectively, with higher As inducing greater phytate exudation and no phytate being detected in tomato exudates. PV treated with phytate+FeAsO4 had higher As and Fe contents and larger biomass than phytate or FeAsO4 treatment, which were 340 vs 20 and 130 mg kg–1 As in the fronds and 7900 vs 1600 and 4100 mg kg–1 Fe in the roots. We hypothesized that As-induced phytate exudation helped PV to take up Fe and As from insoluble FeAsO4 and promoted PV growth. Our study suggests that phytate exudation may be special to fern plants, which may play an important role in enhancing As and nutrient uptake by plants, thereby increasing their efficiency in phytoremediation of As-contaminated soils.
研究领域:
植物学
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环境科学
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DOI
PubMed
高影响因子
ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
·
2013
·Vol. 21
·期 6
·4366-4375
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IF 2.618
Zhang Jianying,Ni Yanyan,Ding Tengda,Zhang Chunlong
Dissolved organic matter (DOM) affects arsenite [As(III)] toxicity by altering its sorption equilibrium at the cell wall interface. A better understanding of such mechanism is of great importance to assess As(III) ecotoxicity in aquatic systems. Batch experiments were conducted to study the effects of DOM on the regulation of As(III) sorption and toxicity in the diatom Navicula sp. The influence of humic acid (HA) on As(III) toxicity was assessed by measuring algal growth, chlorophyll a , and reactive oxygen species (ROS), whereas As(III) mobility across the cell wall was estimated by determining the concentration of intracellular, cell-wall-bound, and free As(III) ions in cell media. Results showed that the effects of HA on arsenite toxicity varied depending on various combinations of As(III)-HA concentrations. EC 50 had an approximate threefold increase from 8.32 (HA-free control) to 22.39 μM (at 20 mg L −1 HA) when Navicula sp. was exposed to 1.0–100.0 μM of As(III), compared to an overall low complexation ratio of HA-As(III) in a range of 0.91–6.00 %. The cell wall-bound and intracellular arsenic content decreased by 19.8 and 20.3 %, respectively, despite the lower arsenite complexation (2.10 ± 0.16 % of the total As). Meanwhile, intracellular ROS was decreased by 12.6 % in response to 10.0 μM As(III) and 10 mg L −1 HA vs. the HA-free control. The significant contrast indicated that complexation alone could not explain the HA-induced reduction in arsenite toxicity and other factors including HA–cell surface interactions may come into play. Isotherms describing adsorption of HA to the Navicula sp. cells combined with morphological data by scanning electron microscopy revealed a protective HA floccule coating on the cell walls. Additional Fourier transform infrared spectroscopic data suggested the involvement of carboxylic groups during the adsorption of both HA and As(III) on the Navicula sp. cell surface. Collective data from this study suggest that cell wall-bound HA can moderate As(III) toxicity through the formation of a protective floccule coating occupying As(III) sorption sites and decreased effective functional groups capable of binding As(III). Our findings imply that As(III) toxicity can be alleviated due to the increased hindrance to cellular internalization of As(III) in the presence of naturally abundant DOM in water.
研究领域:
环境科学
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生态学
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DOI
PubMed
高影响因子
JOURNAL OF MOLECULAR STRUCTURE
·
2021
·
IF 3.196
Yajie Wang,Xianhe Gong,Xin Dong,Yunjie Wu
In this work, arsenite (As(III)) removal in a goethite/oxalate suspension under UVA-irradiation (λ max = 365 nm) was explored under different conditions (initial pH, oxalate concentration, goethite dosage, and phosphate). SEM, EDS, FTIR, XRD and XPS were used to investigate the morphology, composition, functional groups, structure, and surface properites of goethite. The greatest efficiency of As(III) removal was 95.52% at pH 3.0, 100.0 µg·L –1 As(III), 0.05 g·L –1 goethite, and 0.5 mmol·L –1 oxalate. The removal of As(III) in the goethite/oxalate system was strongly pH-dependent. An increase in pH was accompanied by a reduction in photo-oxidation efficiency and an increase in adsorption efficiency. Addition of appropriate amounts of oxalate can enhance As(III) removal at pH 3.0 by promoting the photo-dissolution of iron oxide. However, the addition of oxalate was detrimental to As(III) removal at pH 7.0 due to its competition for photo-generated hole ( h vb + ) as well as adsorption sites. Increasing dosage from 0.0 to 0.5 g·L –1 accelerated As(III) removal at both pH 3.0 and pH 7.0. ESR, radical-scavenging, and N 2 -purging experiments showed that As(III) removal was mainly achieved by photo-oxidation at pH 3.0 and HO · appeared to be the primary oxidant for the As(III) oxidation, which was strongly dependent on HO 2 · /O 2 ·– . However, adsorption served as a major pathway and photo-oxidation played a minor role at pH 7.0. As(III) photo-oxidation was predominantly attributed to the direct reaction between As(III) and h vb + under neutral conditions. In addition, O 2 played an important role in As(III) photo-oxidation under acidic and neutral conditions. Moreover, goethite remained morphologically intact and demonstrated good reusability up to five regeneration cycles. These findings show that As(III) can be effectively removed from water containing iron oxides and carboxylic acid, which is important for the remediation of arsenic-contaminated waterbodies and wastewaters.
研究领域:
环境科学
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化学
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DOI
高影响因子
NEW JOURNAL OF CHEMISTRY
·
2024
·Vol. 48
·期 12
·5311-5325
·
IF 2.7
Pengna Huang,Xianjin Qi,Xiaoxu Duan,Wenqi Jiang,Nina Yang,Gang Zhi,Jianhua Wang
The low adsorption capacity of metal–organic frameworks (MOFs) limits their practical application in high-arsenic wastewater for adsorption owing to their insufficient active sites and suboptimal pore structure. Accordingly, we employed a one-pot hydrothermal method to synthesise mixed-metal La/Zr-MOFs with complex pore structures. Notably, the material possesses both La-BDC and Zr-BDC morphology features and integrates the advantages of monometallic MOFs through a framework symbiotic structure. This complex pore structure promotes the migration and diffusion of arsenic ions in the pore channels, improving the adsorption kinetics. Moreover, mixed-metal functional centres can expose more active sites, which is conducive to enhancing adsorption capacity. Experiments showed that mixed-metal La/Zr-BDC-4 rapidly reached adsorption equilibrium in 60 min, corresponding to a maximum adsorption amount of 694 mg g−1. Batch adsorption experiments and X-ray photoelectron and Fourier-transform infrared spectroscopy analyses revealed that mixed-metal La/Zr-BDC-4 arsenates tend to form internal complexes with each other, suggesting that As(V) adsorption is an exothermic and spontaneous chemisorption process. After four adsorption–desorption cycles, the material maintained an arsenic removal rate of 85%, exhibiting its potential application in wastewater treatment. Therefore, the mixed-metal La/Zr-BDC-4 MOF is a promising material for wastewater treatment.
研究领域:
环境科学
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材料科学
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DOI
高影响因子
INORGANIC CHEMISTRY COMMUNICATIONS
·
2025
·
IF 5.4
Long Zhou,Longwei Yin,Zuliang Chen
Arsenic (As) contamination in groundwater is a growing global environmental issue, and effectively removing both As(III)) and As(V) from groundwater presents a significant challenge. In this study, a novel functional composite, FePd@ZIF-8, was synthesized using a two-step method for the simultaneous removal of As species. It was observed that FePd@ZIF-8 achieved removal efficiencies of 89.42 % for As(V) and 32.74 % for As(III), respectively. Characterization confirmed the successful synthesis of FePd@ZIF-8 and demonstrated that the valence state of As(V) and As(III) remained unchanged during the removal process. XPS and FTIR analyses revealed that the As species was adsorbed onto the surface of the material through complexation. The adsorption isotherms and kinetics indicated that the removal process was dominated by chemisorption. In groundwater applications, FePd@ZIF-8 could still achieve 85.62 and 70.46 % removal efficiency for As(V) and As(III) after four cycles, respectively. This study demonstrates that FePd@ZIF-8 holds significant potential for effectively removing As species from groundwater.
研究领域:
环境科学
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纳米技术
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水处理
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材料科学
·
吸附技术
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产品关联
DOI
高影响因子
ENVIRONMENTAL SCIENCE & TECHNOLOGY
·
2024
·
IF 10.8
Xin Wang,Shengyan Pu,Jiaqi Ding,Jing Chen,Peng Liao,Delai Zhong,Daniel C. W. Tsang,John C. Crittenden,Linling Wang
Clay minerals are ubiquitous in subsurface environments and have long been recognized as having a limited or negligible impact on the fate of arsenic (As) due to their negatively charged surfaces. Here, we demonstrate the significant role of kaolinite (Kln), a pervasive clay mineral, in enhancing As(V) immobilization during ferrous iron (Fe(II)) oxidation at near-neutral pH. Our results showed that Fe(II) oxidation alone was not capable of immobilizing As(V) at relatively low Fe/As molar ratios (≤2) due to the generation of Fe(III)–As(V) nanocolloids that could still migrate easily as truly dissolved As did. In the presence of kaolinite, dissolved As(V) was significantly immobilized on the kaolinite surfaces via forming Kln–Fe(III)–As(V) ternary precipitates, which had large sizes (at micrometer levels) to reduce the As mobility. The kaolinite-induced heterogeneous pathways for As(V) immobilization involved Fe(II) adsorption, heterogeneous oxidation of adsorbed Fe(II), and finally heterogeneous nucleation/precipitation of Fe(III)–As(V) phases on the edge surfaces of kaolinite. The surface precipitates were mixtures of amorphous basic Fe(III)–arsenate and As-rich hydrous ferric oxide. Our findings provide new insights into the role of clay minerals in As transformation, which is significant for the fate of As in natural and engineered systems.
研究领域:
环境科学
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土壤化学
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DOI
PubMed
高影响因子
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
·
2020
·
IF 3.99
Ping Tan,Yixi Zheng,Yongyou Hu
A novel adsorbent CSN-La of lanthanum immobilized on electrospun chitosan nanofiber(CSN) was fabricated and used as adsorbent for arsenate removal. The effects of pH, contact time, arsenate concentration as well as column adsorption were investigated. The results indicated that the arsenate adsorption by CSN-La was pH dependent. The experimental data of arsenic adsorption by CSN-La well fitted pseudo-second-order kinetic model and Langmuir model. The saturated adsorption capacity of CSN-La reached up to 83.6 mg/g, which was significantly higher than that of CSN . CSN-La exhibited preferable arsenate removal in the presence of coexisting anions (chloride, sulfate, nitrate, bicarbonate) at much greater levels. The attractive performance of CSN-La rooted from its special structural characteristics, the host material CSN favored the preconcentration of arsenate through electrostatic attraction, and the immobilized lanthanum exhibited preferable arsenate removal through specific interaction. Column adsorption run by using CSN-La could effectively treat approximately 2650 bed volumes (BV) of feeding solution before breakthrough occurred (from 210 μg/L in influent to < 10 μg/L in effluent). The exhausted CSN-La could be repeatedly used after being eluted by sodium hydroxide solution. The obtained results indicated that CSN-La has a great potential in efficient removal of arsenate-containing water.
研究领域:
环境科学
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材料科学
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DOI
高影响因子
PHOTOCHEMICAL & PHOTOBIOLOGICAL SCIENCES
·
2016
·Vol. 15
·期 3
·431-439
·
IF 2.235
Pozdnyakov Ivan P.,Ding Wei,Xu Jing,Chen Long,Wu Feng,Grivin Vjacheslav P.,Plyusnin Victor F.
Surface complexation between arsenious acid anions (As( iii )) and ferric (hydr)oxides in water is important for the transformation and transfer of inorganic arsenic species. The mechanisms of formation and the photochemistry of dissolved Fe( iii )–As( iii ) complexes in acidic aqueous solution are still unclear. Here, the photooxidation of As( iii ) in the presence of Fe( iii ) ions in acidic media has been investigated by laser flash and steady-state photolysis. At low arsenite concentrations (<1 mM), As( iii ) is oxidized by the ˙OH radical generated by photolysis of the FeOH 2+ complex. At higher arsenite concentrations (>10 mM), photoactive Fe( iii )–As( iii ) complexes are formed ( ϕ 308 Fe ≈ 0.012). At all arsenite concentrations, a white FeAsO 4 colloid is formed during As( iii ) photolysis in the presence of Fe( iii ) ions. Solid Fe( iii )–As( iii ) complexes have been prepared and characterized, and the photochemical transformation of As( iii ) into As( v ) in solid Fe( iii )–As( iii ) complexes has been confirmed. These findings are important for a better understanding of the evolution of As( iii ) species under environmental conditions and should provide guidance for detoxification of As( iii )-polluted water systems.
研究领域:
环境科学
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化学
✓ 已验证
DOI
PubMed
高影响因子
ENVIRONMENTAL POLLUTION
·
2020
·
IF 6.793
Fan Zhang,Xue Li,Lizeng Duan,Hucai Zhang,Wen Gu,Xingxin Yang,Jingping Li,Sen He,Jie Yu,Meijie Ren
Dissolved organic matter (DOM) and dissolved ions are two integral parameters to affect the environmental fate of As in different ways. Numerous studies chose surrogate of DOM, humic substances (HSs), to investigate the As complexation behavior. However, microbial secretion (protein and polysaccharide) was also considered for a great proportion in surface aquatic system, and its effect was still not fully understood. The present research distinguished the As complexation behavior with different DOM components (HSs, protein, polysaccharide and synthetic organic matter) in natural and simulated water samples. The results indicated that different DOM components exhibited various binding capacities for As. HSs showed the strongest affinity for As, followed by long-chain compounds (polysaccharide and synthetic organic matter) and proteins. In water source, HSs were probably the primary parameter for As complexation. In eutrophic water system, however, polysaccharide maybe the main DOM component to bind As. Cationic bridge function was prone to occur in the presence of HSs, but not observed in the presence of protein. PO 4 3− competed for binding sites with As, consequently decreasing the As complexation with all the DOM components. The research implied that a comprehensive and meticulous analyses of DOM fractions and coexist ions are the prerequisite to understanding the behavior of As (or other pollutants) in different natural aquatic systems.
研究领域:
环境科学
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水文学
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DOI
PubMed
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
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材料科学
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PubMed
高影响因子
危险品化学品经营许可证（带存储）