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Showing 1 to 20 of 56 for “"As (III)"”.
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Characterization Of Arsd: An Arsenic Chaperone For The Arsab As(iii)-Translocating Atpase
… a variety of health and environment problems. As an adaptation to arsenic-contaminated environments, organisms have developed resistance systems. In bacteria and archaea various ars operons encode ArsAB ATPases that pump the trivalent metalloids As(III) or Sb(III) out of cells. In these …
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The kinetics of the Arsenic(III)-Chromium(VI) reaction in various buffer solutions
The oxidation of arsenic(III) by chromium(VI) requires the postulation of uncommon oxidation states as reactive intermediates. The possible intermediates of chromium are the divalent, tetravalent, and pentavalent states. Recently arsenic(IV) has been postulated as a reactive intermediate in certain …
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Microbial Oxidation of Arsenite in Anoxic Environments: Impacts on Arsenic Mobility
AbstractArsenic (As) contamination of groundwater and surface water is a worldwide problem. Exposure to arsenic in drinking water is an important current public health issue. Arsenic is well known for its carcinogenic and teratogenic effects. The U.S. Environmental Protection Agency (USEPA) has …
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Sorptions- und Redoxprozesse von Arsen an oxidischen Oberflächen : experimentelle Untersuchungen
… der anorganischen Arsenspezies (As(III) und As(V)) hat einen entscheidenden Einfluss auf die Toxizität und Mobilität des Elements. Im Grundwasserleiter finden eine Vielzahl von Sorptions- und Redoxreaktionen zwischen Feststoffen und den gelösten Arsenspezies statt. Manganoxide und …
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Arsenic Adsorption on Iron Oxides in the Presence of Soluble Organic Carbon and the Influence of Arsenic on Radish and Lettuce Development
… is available on the survival, uptake, and dry mass production of vegetable seedlings and maturing plants in arsenic enriched environments. Such information is however very important to many vegetable growers in areas of subsistent agricultural like Bangladesh or home-gardeners in closer …
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A kinetic study of the chromium (VI) - arsenic (III) reaction in pyridine-pyridinium buffer solutions containing oxalate
The oxidation of arsenic (III) by chromium (VI) has been studied in pyridine - pyridinium buffers with and without added oxalate ion. The rate law at pH 4.6 for the reactions without oxalate is best described as - d[Cr(VI)]/dt = (0.535 [As(III)]² [Cr(VI)])/(1+187 [As(III)]) This is in accord with …
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Role of Sodium Arsenite in Atherogenesis
Epidemiological studies as well as controlled animal studies have associated exposure to arsenic through drinking water with the development of atherosclerosis. In this study, we have shown for the first time that low and environmentally relevant concentrations of arsenic accelerate atherogenesis. …
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Role of Sodium Arsenite in Atherogenesis
Epidemiological studies as well as controlled animal studies have associated exposure to arsenic through drinking water with the development of atherosclerosis. In this study, we have shown for the first time that low and environmentally relevant concentrations of arsenic accelerate atherogenesis. …
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Characterization of Arsenic by High Performance Liquid Chromatography and Inductively Coupled Plasma Mass Spectrometry of Algal Extracts and Water in Evaporation Ponds
… method to accurately determine the concentration as well as the speciation of arsenic in highly complex evaporation pond water and algae will be discussed. Interestingly, microorganisms are thriving in evaporation ponds that have high levels of arsenic, which is unusual for their survival. This …
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Synthesis and potential application of Fe3+/Mn2+ bimetal and hexadecyltrimethylammonium bromide (HDTMA-Br) modified clayey soils for arsenic removal in groundwater
The presence of arsenic in groundwater has drawn worldwide attention from researchers and public health officials due to its effects on human health such as, cancer, skin thickening, neurological disorders, muscular weakness, loss of appetite and nausea. World Health Organisation (WHO) has set the …
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Arsenic speciation by ion-exchange chromatography with on- line determination by hydride generation: electronic modification of the D.C. plasma by photon counting
… for the determination of arsenous acid (As(III)), arsenic acid (As(V)), monomethylarsonic acid (MMAA), and dimethylarsinic acid (DMAA) by hydride generation was demonstrated. The instrument used was a d.c. plasma atomic emission spectrometer (OCP-AES). Complete recovery was reported for …
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Novel treatment technologies for arsenic removal from water
… on the environment. Arsenic pollution in water has been found in many parts of the world, especially in developing countries such as Bangladesh, India, Nepal, and Vietnam. It is also detected in some areas of Australia. In rural area of Victoria, arsenic concentrations of up to 8 μg/L and 220 …
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Corrosion and corrosion suppression on n-type gallium arsenide semiconductor liquid-junction solar cells
N-type GaAs is a potentially useful semiconductor in liquid junction type solar cells. Corrosion and corrosion suppression on an n-type GaAs semiconductor in both light and dark has been studied. The application of non-electroactive layers for corrosion suppression on semiconductor electrodes is a …
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The Effect of Speciation and Form on the Bioavailability of Arsenic: Insight into the Behavior of Arsenic in Natural Waters
… water supplies contaminated with arsenic (As), a toxin and carcinogen, adversely impact the health of millions of people worldwide. Previous work has documented that different inorganic and organic As species vary with respect to their toxicities. It is, however, currently not well …
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Bindungsformen und Mobilität von Arsen in Moorböden
… der Umwelt vorkommt. Moorböden bilden Senken für As, obwohl sie zumeist anoxische Bedingungen aufweisen, unter denen As eher mobil sein sollte als unter oxischen Bedingungen. Arsen besitzt eine Affinität zu oxidischen Oberflächen, aber die Bedeutung der organischen Substanz für die Bindung von As …
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Competitive Adsorption of Arsenite and Silicic Acid on Goethite
… at environmentally relevant concentrations was investigated utilizing pH adsorption data and zeta potential measurements. Both addition scenarios (Si before As(III) and As(III) before Si) were examined. The results of the adsorption experiments and zeta potential measurements were then used …
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Coupled arsenic, iron, and nitrogen cycling in arsenic-contaminated Upper Mystic Lake
… addresses the mechanisms controlling arsenic (As) remobilization and cycling in the hypolimnion of As-contaminated Upper Mystic Lake (UML; Winchester, MA). We conducted field and laboratory studies, and applied mass balance, surface complexation, and thermodynamic modeling to explore As cycling …
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A Reinvestigation of Salvarsan and Related Arsenic Chemistry.
… related species. A series of arylarsonic acids was prepared and fully characterised by electrospray mass spectrometry, NMR and X-ray crystallography for six examples. A detailed analysis of the hydrogen bonding in crystals of these molecules showed that they adopt several characteristic motifs …
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THREE STUDIES OF 2-PYRIDONE PHOTOADDUCT REACTIVITY
2-Pyridones such as iii undergo efficient [4+4] photocycloaddition reactions, yielding strained tricyclic cyclooctadiene structures iv and v, with functionality at every carbon. As part of a program to develop the chemistry of these complex adducts, three studies have been conducted. Halogenation …
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Colorimetric determination and speciation of arsenic with silver diethyldithiocarbamate
… the improved procedure is 5 {dollar}\mu{dollar}g As/L (0.5 {dollar}\mu{dollar}g As). Due to the varied toxicity of arsenic compounds and oxidation states in the environment, speciation techniques are important. A review of the literature regarding the determination of individual arsenic species is …
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