کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
4483611 1316893 2008 9 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Anoxic oxidation of arsenite linked to denitrification in sludges and sediments
موضوعات مرتبط
مهندسی و علوم پایه علوم زمین و سیارات فرآیندهای سطح زمین
پیش نمایش صفحه اول مقاله
Anoxic oxidation of arsenite linked to denitrification in sludges and sediments
چکیده انگلیسی

In this study, denitrification linked to the oxidation of arsenite (As(III)) to arsenate (As(V)) was shown to be a widespread microbial activity in anaerobic sludge and sediment samples that were not previously exposed to arsenic contamination. When incubated with 0.5 mM As(III) and 10 mM NO3−, the anoxic oxidation of As(III) commenced within a few days, achieving specific activities of up to 1.24 mmol As(V) formed g−1 volatile suspended solids d−1 due to growth (doubling times of 0.74–1.4 d). The anoxic oxidation of As(III) was partially to completely inhibited by 1.5 and 5 mM As(III), respectively. Inhibition was minimized by adding As(III) adsorbed onto activated aluminum (AA). The oxidation of As(III) was shown to be linked to the complete denitrification of NO3− to N2 by demonstrating a significantly enhanced production of N2 beyond the background endogenous production as a result of adding As(III)–AA to the cultures. The N2 production corresponded closely the expected stoichiometry of the reaction, 2.5 mol As(III) mol−1 N2–N. The oxidation of As(III) linked to the use of common-occurring nitrate as an electron acceptor may be an important missing link in the biogeochemical cycling of arsenic.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Water Research - Volume 42, Issue 17, November 2008, Pages 4569–4577
نویسندگان
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