Arsenic in the environment: Biology and Chemistry

Bhattacharya, Prosun; Welch, Alan H.; Stollenwerk, Kenneth G.; McLaughlin, Michael J.; Bundschuh, Jochen; Panaullah, G. M.

doi:10.1016/j.scitotenv.2007.02.037

Cited by 508 publications

(167 citation statements)

References 84 publications

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“…As(III) exists as H 3 AsO 3 when the pH is below 8.0. At pH values above 8.0, As(III) is gradually negatively charged, changing from H 2 AsO 3 − to HAsO 3 2− and finally to AsO 3 3− . 64 Because As(III) is gradually negatively charged when the pH is above 8.0, it is reasonable that the adsorption capacity decreases considerably for pH values above 11.0.…”

Section: Acs Applied Materials and Interfacesmentioning

confidence: 99%

Zirconia (ZrO₂) Embedded in Carbon Nanowires via Electrospinning for Efficient Arsenic Removal from Water Combined with DFT Studies

Luo

et al. 2016

ACS Appl. Mater. Interfaces

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To use zirconia (ZrO 2 ) as an efficient environmental adsorbent, it can be impregnated on a support to improve its physical properties and lower the overall cost. In this study, ZrO 2 embedded in carbon nanowires (ZCNs) is fabricated via an electrospinning method to remove arsenic (As) from water. The maximum adsorption capacity values of As(III) and As(V) on the ZCNs are 28.61 and 106.57 mg/g, respectively, at 40°C. These capacities are considerably higher than those of pure ZrO 2 (2.56 and 3.65 mg/g for As(III) and As(V), respectively) created using the same procedure as for the ZCNs. Meanwhile, the adsorption behaviors of As(III) and As(V) on the ZCNs are endothermic and pH dependent and follow the Freundlich isotherm model and pseudo-first-order kinetic model. Both As(III) and As(V) are chemisorbed onto the ZCNs, which is confirmed by a partial density of state (PDOS) analysis and Dubinin−Radushkevich (D-R) model calculations. Furthermore, the ZCNs also possess the capability to enhance or catalyze the oxidation process of As(III) to As(V) using dissolved oxygen. This result is confirmed by a batch experiment, XPS analysis and Mulliken net charge analysis. Density functional theory (DFT) calculations indicate the different configurations of As(III) and As(V) complexes on the tetragonal ZrO 2 (t-ZrO 2 )(111) and monoclinic ZrO 2 (m-ZrO 2 )(111) planes, respectively. The adsorption energy (E ad ) of As(V) is higher than that of As(III) on both the tZrO 2 (111) and m-ZrO 2 (111) planes (3.38 and 1.90 eV, respectively, for As(V) and 0.37 and 0.12 eV, respectively, for As(III)).

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Section: Acs Applied Materials and Interfacesmentioning

confidence: 99%

Zirconia (ZrO₂) Embedded in Carbon Nanowires via Electrospinning for Efficient Arsenic Removal from Water Combined with DFT Studies

Luo

et al. 2016

ACS Appl. Mater. Interfaces

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“…As(V) predominates in surface waters, while groundwater may also contain relevant concentrations of As(III) that are more mobile and toxic than As(V) [2]. Elevated concentrations of arsenic in groundwaters of China are the result of biogeochemical processes [3] or anthropogenic activities such as agriculture (the extensive use of herbicides and insecticides) and irregular disposal of hazardous waste from heavy industry [4][5].…”

mentioning

confidence: 99%

Continuous Fixed-Bed Column Study and Adsorption Modeling: Removal of Arsenate and Arsenite in Aqueous Solution by Organic Modified Spent Grains

Chen¹,

Wu²,

Chen³

et al. 2017

Pol. J. Environ. Stud.

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Arsenic is of environmental concern because of its toxicity to plants, animals, and humans. Arsenic in drinking water has the greatest impact on the general population and human health. In natural waters arsenic can be found in inorganic forms as oxidized pentavalent arsenate (As(V)) or trivalent arsenite (As(III)), mostly as H 2 AsO 4 -, HAsO 4 2-, H 3 AsO 3 , and H 2 AsO 3 - [1]. As(V) predominates in surface waters, while groundwater may also contain relevant concentrations of As(III) that are more mobile and toxic than As(V) [2]. Elevated concentrations of arsenic in groundwaters of China are the result of biogeochemical processes [3] or anthropogenic activities such as agriculture (the extensive use of herbicides and insecticides) and irregular disposal of hazardous waste from heavy industry [4][5].Long-term exposure through drinking water to even low concentrations of arsenic (≤50 μg/l) can cause Pol. J. Environ. Stud. Vol. 26, No. 4 (2017), 1847-1854 The adsorption of arsenate (As(V)) and arsenite (As(III)) was conducted in a continuous fixed-bed column by using organic modified spent grains (OSGs). The column performances were evaluated by varying the influent flow rate (0.91, 1.36, and 2.72 ml/min) and arsenic ions initial concentration (1.0, 2.0, and 6.0 mg/l for As(V); 0.5, 1.0, and 3.0 mg/l for As(III)) in order to obtain experimental breakthrough curves. The maximum adsorption capacity was at 6.0 mg/l for As(V) and 3.0 mg/l for As(III) influent concentration and 1.36 ml/min flow rate. The Thomas model, Adams-Bohart model, and Yoon-Nelson kinetic models were used to analyze column performance. The value of rate constant for Thomas and Adams-Bohart models decreased with increase of influent concentration, but increased with increasing flow rate. The rate constant for the Yoon-Nelson model decreased with increases in both initial influent arsenic ions concentration and flow rate.

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“…Arsenic may be found in soil as inorganic species as well as binding to organic compounds; however, it exists predominantly as inorganic species in soil. Inorganic As compounds may undergo methylation by microorganisms, producing, under oxidizing conditions, monomethylarsonic acid, dimethylarsinic acid, and trimethylarsine oxide [2,45,46]. Principle factors affecting the level of As in soils include the parent rock, climate, organic and inorganic components of the soil, and redox potential status [41,47].…”

Section: Occurrence Of Arsenic In Soilmentioning

confidence: 99%

“…enter air, water, and surface environments through wind-blown dust and runoff [1][2][3]. The primary source of As is natural, derived mainly from the interactions between groundwater and aquifer sediments and hard rocks of minerals, particularly pyrite (FeS 2 ), arsenopyrite (FeAsS), and other unspecified sulfide minerals [4][5][6], as well as secondary As-bearing minerals or mineral coatings, whereas industrial uses, agricultural activities, coal and oil exploitation and combustion, and mining of metal ores are anthropogenic sources that release As into groundwaters [7,8].…”

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confidence: 99%

Natural Arsenic in Global Groundwaters: Distribution and Geochemical Triggers for Mobilization

et al. 2016

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The elevated concentration of arsenic (As) in the groundwaters of many countries worldwide has received much attention during recent decades. This article presents an overview of the natural geochemical processes that mobilize As from aquifer sediments into groundwater and provides a concise description of the distribution of As in different global groundwater systems, with an emphasis on the highly vulnerable regions of Southeast Asia, the USA, Latin America, and Europe. Natural biogeochemical processes and anthropogenic activities may lead to the contamination of groundwaters by increased As concentrations. The primary source of As in groundwater is predominantly natural (geogenic) and mobilized through complex biogeochemical interactions within various aquifer solids and water. Sulfide minerals such as arsenopyrite and As-substituted pyrite, as well as other sulfide minerals, are susceptible to oxidation in the near-surface environment and quantitatively release significant quantities of As in the sediments. The geochemistry of As generally is a function of its multiple oxidation states, speciation, and redox transformation. The reductive dissolution of As-bearing Fe(III) oxides and sulfide oxidation are the most common and significant geochemical triggers that release As from aquifer sediments into groundwaters. The mobilization of As in groundwater is controlled by adsorption onto metal oxyhydroxides and clay minerals. According to recent estimates, more than 130 million people worldwide potentially are exposed to As in drinking water at levels above the World Health Organization's (WHO's) guideline value of 10 μg/L. Hence, community education to strengthen public awareness, the involvement and capacity building of local stakeholders in targeting As-safe aquifers, and direct action and implementation of best practices in identifying safe groundwater sources for the installation of safe drinking water wells through action and enforcement by local governments and international water sector professionals are urgent necessities for sustainable As mitigation on a global scale.

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Arsenic in the environment: Biology and Chemistry

Cited by 508 publications

References 84 publications

Zirconia (ZrO₂) Embedded in Carbon Nanowires via Electrospinning for Efficient Arsenic Removal from Water Combined with DFT Studies

Zirconia (ZrO₂) Embedded in Carbon Nanowires via Electrospinning for Efficient Arsenic Removal from Water Combined with DFT Studies

Continuous Fixed-Bed Column Study and Adsorption Modeling: Removal of Arsenate and Arsenite in Aqueous Solution by Organic Modified Spent Grains

Natural Arsenic in Global Groundwaters: Distribution and Geochemical Triggers for Mobilization

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Arsenic in the environment: Biology and Chemistry

Cited by 508 publications

References 84 publications

Zirconia (ZrO2) Embedded in Carbon Nanowires via Electrospinning for Efficient Arsenic Removal from Water Combined with DFT Studies

Zirconia (ZrO2) Embedded in Carbon Nanowires via Electrospinning for Efficient Arsenic Removal from Water Combined with DFT Studies

Continuous Fixed-Bed Column Study and Adsorption Modeling: Removal of Arsenate and Arsenite in Aqueous Solution by Organic Modified Spent Grains

Natural Arsenic in Global Groundwaters: Distribution and Geochemical Triggers for Mobilization

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Zirconia (ZrO₂) Embedded in Carbon Nanowires via Electrospinning for Efficient Arsenic Removal from Water Combined with DFT Studies

Zirconia (ZrO₂) Embedded in Carbon Nanowires via Electrospinning for Efficient Arsenic Removal from Water Combined with DFT Studies