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http://repositoriodigital.ipn.mx/handle/123456789/11453
Título : | Arsenic(III) methylation in betaine–nontronite clay–water suspensions under enviromental conditions |
Palabras clave : | Methyl transfer Toxicity |
Fecha de publicación : | 16-ene-2013 |
Editorial : | ELSEVIER |
Descripción : | This paper reports arsenic methylation in betaine–nontronite clay–water suspensions under environmental conditions. Two nontronites (<0.05 mm), NAu-1 (green color, Al-enriched) and NAu-2 (brown color, Al-poor, contains tetrahedral Fe) from Uley Mine - South Australia were selected for this study. Betaine (pKa = 1.83) was selected as methyl donor. The reaction between 5 g L−1 clay, 20ppm As(III), and 0.4M betaine at 7≤pH0 ≤9 under anoxic conditions was studied. The presence of nontronite clays were found to favor As(III) conversion to monomethylarsenic (MMA). Arsenic conversion was found to be as high as 50.2 ngMMA/ng As(III)0. Conversion of As was found to be more quantitative in the presence of NAu-2 ((Na0.72) [Si7.55 Al0.16Fe0.29][Al0.34 Fe3.54 Mg0.05] O20(OH)4) than NAu-1 ((Na1.05) [Si6.98 Al0.95Fe0.07][Al0.36 Fe3.61 Mg0.04] O20(OH)4). The inherent negative charge at the nontronite tetrahedral layer stabilizes positively charged organic intermediate-reaction species, thereby leading to decreases in the overall methylation activation energy. The outcome of this work shows that nontronite clays catalyze As methylation to MMA via non-enzymatic pathway(s) under environmental conditions. |
URI : | http://www.repositoriodigital.ipn.mx/handle/123456789/11453 |
Otros identificadores : | http://hdl.handle.net/123456789/973 |
Aparece en las colecciones: | Doctorado |
Ficheros en este ítem:
Fichero | Descripción | Tamaño | Formato | |
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RESUMEN ARSENIC.docx | 17.5 kB | Microsoft Word XML | Visualizar/Abrir |
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