• Environmental Analysis Health and Toxicology
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• v.21 no.1 s.52
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• pp.1-11
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• 2006

Arsenic is a ubiquitous element found in several forms in environment. Although certain foods, such as marine fish, contain substantial levels of organic arsenic forms, they are relatively low in toxicity compared to inorganic forms. In contrast, arsenic in drinking water is predominantly inorganic and very toxic. Chronic ingestion of arsenic-contaminated drinking water is therefore the major pathway posing potential risk to human health. World populations are exposed to low to moderate levels of arsenic of parts per billion (ppb) to thousands of ppb. When exposed to human, it could metabolize into monomethylarsonous acid ($MMA^{III}$) and dimethylarsinous acid ($DMA^{III}$) which are highly toxic. Lots of stuides have been recently focused how $MMA^{III}\;and\;DMA^{III}$ induce toxic insults in various target tissues. Epidemiological studies revealed that chronic arsenic exposure caused cancer, cardiovascular diseases, and diabetes etc. In this review, the current understanding of arsenic on health effects will be discussed.

• Analytical Science and Technology
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• v.13 no.2
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• pp.189-193
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• 2000

Arsenic (III) and arsenic (V) in disused mine tailing samples have been determined simutaneuously by hydride generation inductively coupled plasma atomic emission spectrometry (HG-ICP-AES). Total arsenic was determined using 2% $NaBH_4$ and 6 M HCl after prereduction of As(V) to As(III) with) 1M KI. Arsenic (III) was determined selectively using citrate/citric acid buffer with range of pH 5-6, it was determined by HG-ICP-AES. Arsenic (V) can be evaluated by the differences. According to the results, arsenic (V) was over 90% among the total arsenic extracted from disused mine tailing samples.

• Journal of Korean Society of Water and Wastewater
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• v.25 no.1
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• pp.15-21
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• 2011

Arsenic is one of the most abundant contaminant found in waste mine tailings, because of it's carcinogenic property, the countries like United states of America and Europe have made stringent regulations which govern the concentration of arsenic in drinking water. The current study focuses on different treatment methods for removal of arsenic from waste water. Treatment method the high strength arsenic waste water is treated with Fe(III)-ettringite by co-precipitation method. Number of experiments were carried out to decide the optimal dosage of Fe(III)-ettringite to treat arsenic waste water. The Fe(III)-ettringite was synthesized by taking appropriate equivalent ratios of calcium oxide and ferric chloride in proportion to the arsenic. The best removal efficiencies of 94% were observed at a As/(Ca: Fe) ratio of 1:3. The maximum removal of arsenic was observed in pH range of 12. But as the pH increases the arsenic removal efficiency decreases as portlandite is formed in the pH above 12. The analysis of surface of precipitate conform the needle like structure of ettringite. This treatment technique has promising features such as, the chemicals required in the treatment as well as the sludge generated can be reduced. The operating pH range is in alkaline region which is advantageous over traditional treatment process which has lower pH. Also the co-precipitation not only helps in removal of arsenic but also heavy metals.

• Microbiology and Biotechnology Letters
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• v.42 no.3
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• pp.238-248
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• 2014

The metalloid arsenic (Z = 33) is considered to be a significant potential threat to human health due to its ubiquity and toxicity, even in rural regions. In this study a rural region contaminated with arsenic, located at longitude $85^{\circ}$ 32'E and latitude $25^{\circ}$ 11'N, was initially examined. Arsenic tolerant bacteria from the rhizosphere of Amaranthas viridis were found and identified as Bacillus licheniformis through 16S rRNA gene sequencing. The potential for the uptake and removal of arsenic at 3, 6 and 9 mM [As(V)], and 2, 4 and 6 mM [As(III)], and for the reduction of the above concentrations of As(V) to As(III) by the Bacillus licheniformis were then assessed. The minimal inhibitory concentrations (MIC) for As(V) and As(III) was determined to be 10 and 7 mM, respectively. At 3 mM 100% As(V) was uptaken by the bacteria with the liberation of 42% As(III) into the medium, whereas at 6 mM As(V), 76% AS(V) was removed from the media and 56% was reduced to As(III). At 2 mM As(III), the bacteria consumed 100%, whereas at 6 mM, the As(III) consumption was only 40%. The role of pH was significant for the speciation, availability and toxicity of the arsenic, which was measured as the variation in growth, uptake and content of cell protein. Both As(V) and As(III) were most toxic at around a neutral pH, whereas both acidic and basic pH favored growth, but at variable levels. Contrary to many reports, the total cell protein content in the bacteria was enhanced by both As(V) and As(III) stress.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2003.09a
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• pp.78-82
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• 2003

Development of hematite-coated sand was evaluated for the application of the PRB (permeable reactive barrier) in the arsenic-contaminated subsurface of the metal mining areas. The removal efficiency of As(III) and As(V), the effect of anion competition and the capability of arsenic removal in the flow system were investigated through the experiments of adsorption isotherm, arsenic removal kinetics against anion competition and column removal. Hematite-coated sand followed a linear adsorption isotherm with high adsorption capacity at low level concentrations of arsenic (< 1.0 mg/l). When As(III) and As(V) underwent adsorption reactions in the presence of anions (sulfate, nitrate and bicarbonate), sulfate caused strong inhibition of arsenic removal, and bicarbonate and nitrate caused weak inhibition due to specific and nonspecific adsorption onto hematite, respectively. In the column experiments, high content of hematite-coated sand enhance the arsenic removal, but the amount of the arsenic removal decreased due to the higher affinity of As(V) than As(III) and reduced adsorption kinetics in the flow system, Therefore, the amount of hematite-coated sand, the adsorption affinity of arsenic species and removal kinetics determined the removal efficiency of arsenic in the flow system. arsenic, hematite-coated sand, permeable reactive barrier, anion competition, adsorption.

• Bulletin of the Korean Chemical Society
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• v.24 no.12
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• pp.1805-1808
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• 2003

The simultaneous determination of As(III), As(V), and DMA has been performed by ion chromatography (IC) coupled with inductively coupled plasma-mass spectrometry (ICP-MS). The separation of the three arsenic species was achieved by an anionic separator column (AS 7) with an isocratic elution system. The separated species were directly detected by ICP-MS as an element-selective detection method. The IC-ICP-MS technique was applied for the determination of arsenic species in a NIST SRM 1643d water sample. An As(III) only was detected in the sample. The detection limits of As(III), As(V) and DMA were 0.31, 0.45, and 2.09 ng/mL, respectively. It was also applied for the determination of arsenic species in a human urine obtained by a volunteer, and three arsenic species were identified. The determination of total As in human urines that were obtained from 25 volunteers at the different age was also carried out by ICP-MS.

• Analytical Science and Technology
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• v.5 no.4
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• pp.417-423
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• 1992

The effects of metal ions on the arsenic(III) stripping peak were examined by the cathodic stripping voltammetry. The reduction stripping peak potential and current of arsenic(III) value were -0.79V(vs. Ag/AgCl). $0.86{\mu}A$ by using 0.1N-hydrochloric acid solution. When 10 times of Cu(II) was added to the solution, the reduction stripping peak potential of arsenic(III) was the value of -0.84V(vs. Ag/Cl), which showed a good agreement with theoretical value -0.84V(vs. Ag/Cl) by using 0.1N hydrochloric acid solution. Lead(II) and copper(II) increased the stripping peak heigh of arsenic(III), Among them, the copper(II) extremely enhanced it.

• Journal of Environmental Impact Assessment
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• v.24 no.4
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• pp.344-351
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• 2015

In this study, bio-electrokinetics was used to increase migration of arsenic by activating endemic microorganisms in the soil. In this technology, bio-electrokinetics which the cultured soil microorganisms and nutrients injected combines with biological technology. This technology using electrical movement of microorganisms could overcome the weakness of late degradation speed and low removal efficiency. And, various soil microorganisms reduce ferreous, manganese, etc., using organic matter by as an electron donor by injecting mixture of soil microorganisms and nutrients instead of using electrolyte of the electrode. Accordingly, surrounding metal oxide microorganisms convert arsenic (III) to arsenic (V) to increase migration of arsenic (III), in consequence, migration of arsenic increased in 60 to 70% compared to about 30% of conventional electrokinetics.

• Microbiology and Biotechnology Letters
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• v.51 no.1
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• pp.1-9
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• 2023

Arsenic (As), which is ubiquitous throughout the environment, represents a major environmental threat at higher concentration and poses a global public health concern in certain geographic areas. Most of the conventional arsenic remediation techniques that are currently in use have certain limitations. This situation necessitates a potential remediation strategy, and in this regard bioremediation technology is increasingly important. Being the oldest representativse of life on Earth, microbes have developed various strategies to cope with hostile environments containing different toxic metals or metalloids including As. Such conditions prompted the evolution of numerous genetic systems that have enabled many microbes to utilize this metalloid in their metabolic activities. Therefore, within a certain scope bacterial isolates could be helpful for sustainable management of As-contamination. Research interest in microbial As(III) oxidation has increased recently, as oxidation of As(III) to less hazardous As(V) is viewed as a strategy to ameliorate its adverse impact. In this review, the novelty of As(III) oxidation is highlighted and the implication of As(III)-oxidizing microbes in environmental management and their prospects are also discussed. Moreover, future exploitation of As(III)-oxidizing bacteria, as potential plant growth-promoting bacteria, may add agronomic importance to their widespread utilization in managing soil quality and yield output of major field crops, in addition to reducing As accumulation and toxicity in crops.

• Bulletin of the Korean Chemical Society
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• v.31 no.11
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• pp.3077-3083
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• 2010

The electrochemical detection of As(III) was investigated on a platinum-iron(III) nanoparticles modified multiwalled carbon nanotube on glassy carbon electrode(nanoPt-Fe(III)/MWCNT/GCE) in 0.1 M $H_2SO_4$. The nanoPt-Fe(III)/MWCNT/GCE was prepared via continuous potential cycling in the range from -0.8 to 0.7 V (vs. Ag/AgCl), in 0.1 M KCl solution containing 0.9 mM $K_2PtCl_6$ and 0.6 mM $FeCl_3$. The Pt nanoparticles and iron oxide were co-electrodeposited into the MWCNT-Nafion composite film on GCE. The resulting electrode was examined by cyclic voltammetry (CV), scanning electron microscopy (SEM), and anodic stripping voltammetry (ASV). For the detection of As(III), the nanoPt-Fe(III)/MWCNT/GCE showed low detection limit of 10 nM (0.75 ppb) and high sensitivity of $4.76\;{\mu}A{\mu}M^{-1}$, while the World Health Organization's guideline value of arsenic for drinking water is 10 ppb. It is worth to note that the electrode presents no interference from copper ion, which is the most serious interfering species in arsenic detection.