Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 15 of 15 for “"Arsenic Speciation"”.
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Arsenic Speciation in Food
… , arsenite and arsenate. Using this coupling, arsenic species in fruit and vegetables grown on soils containing up to 1.4% w\w arsenic have been surveyed and DMAA, MMAA, arsenite and arsenate identified in the plants. Although extraction efficiencies were poor, typically 10%, total arsenic …
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Total arsenic and arsenic speciation in indigenous food stuffs
… on its chemical form, it’s called elemental speciation. This study evaluates the arsenic species found in a range of food stuffs together with growing environments and toxicity issues. Total arsenic concentrations in fish tissue and vegetable crops were determined by ICP-MS following …
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Arsenic speciation and evaluation of an adsorption media in Rupandehi and Nawalparasi districts of Nepal
Thesis (M.Eng.)--Massachusetts Institute of Technology, Dept. of Civil and Environmental Engineering, 2002.
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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
… 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 As(III), …
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Analytical methods to investigate occupational exposure to toxic elements and their species
… methodologies and,the development of novel speciation methodologies, including single particle analysis. It furthers biological monitoring research of elements that are of a carcinogenic occupational concern, i.e. inorganic arsenic, hexavalent chromium and respirable crystalline silica …
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Continued optimization of a microelectrolysis treatment process for removal of arsenic from landfill gas condensate, characterization of materials, and evaluation of Fe as a predictor of treatment monitoring
… (LGC) are known to contain high levels of arsenic whose presence may result in exceeding applicable discharge limits. Arsenic speciation in LGC is dominated by organo-As compounds that are difficult or impossible to remove by conventional methods. This difficulty may be circumvented via …
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Controls on arsenic mobility in contaminated wetland and riverbed streams
Arsenic mobility and transport in the environment are strongly influenced by associations with solid phases. This dissertation investigates the mechanisms affecting arsenic retention in contaminated wetland and riverbed sediments. A sequential extraction procedure was designed and tested to …
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Arsenic and other trace elements in Bangladeshi food and non-food and their relationship to human health
… that over 30 million people are exposed to arsenic from drinking contaminated groundwater in Bangladesh. Furthermore, due to the use of contaminated water for irrigation purposes, arsenic and other toxic elements are entering the food chain of Bangladeshis. In this thesis, the total levels …
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Microbial transformation of arsenic in Bengal floodplain
Presence of arsenic in paddy soils in Bangladesh has become a major concern, with Holocene soils reported to have higher levels of arsenic compared to Pleistocene. However, to date there is limited data on how geomorphology, land use and soil microbes drive bioavailability of arsenic in the paddy …
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Speciation and microbial transformation of chromium, arsenic and mercury in municipal landfill leachate
… by waste disposal guidelines. Chromium, arsenic and mercury speciation were investigated in municipal landfill leachate (MLL) to evaluate microbial transformation of the heavy metals in the landfill system. MLL is a complex matrix that contains multiple inorganic and organic contaminants, …
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An Investigation of Inorganic Background Soil Constituents With a Focus on Arsenic Species
… abundances of metals and, in particular, arsenic within soils of various geological units. These units included the Quaternary Aeolian (Qpw) (highest concentration of zinc, lowest concentration of chromium) the Quaternary Fluvial (Qrc) (highest chromium and nickel, equal highest copper, …
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Effect of soil amendments on the chemical transformation of arsenic and the microbial diversity in rice paddy microbiome
Paddy management practices greatly influence arsenic biogeochemistry. For sustainable rice production, rice needs to be free from arsenic. Different soil amendments such as animal manure in flooded paddy soil could enhance arsenic reductive mobilization, biomethylation, and volatilization which …
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Elemental speciation and miniaturised sample introduction studies for inductively coupled plasma mass spectrometry
… aim is to develop methods for conducting rapid speciation analysis. This is approached in two ways; firstly using liquid chromatography (LC) employing a column with a monolithic silica stationary phase, and secondly by the development of a highly efficient sample introduction system designed for …
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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
Arsenic is a toxic element and its effects on humans, animals and other organisms are well documented. A 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 …
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Environmental mineralogy of gold recovery from refractory gold-arsenic-bearing Bakyrchik concentrates
Arsenic contamination of groundwater associated with mining operations is a widespread problem across the globe. The release of arsenic (As) into the environment occurs naturally by oxidation of exposed sulfide minerals. In the case of gold ores, the mining and beneficiation may also produce …