کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
6307407 1618833 2015 13 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Microbial community composition of a household sand filter used for arsenic, iron, and manganese removal from groundwater in Vietnam
ترجمه فارسی عنوان
ترکیب جامعه میکروبی یک فیلتر شن و ماسه خانگی برای حذف آرسنیک، آهن و منگنز از آبهای زیرزمینی در ویتنام
کلمات کلیدی
اکسیداسیون آهن، اکسیداسیون منگنز، اکسیداسیون آرسنیت، اکسیداسیون آمونیاک، فیلتر تصفیه آب آب آشامیدنی،
موضوعات مرتبط
علوم زیستی و بیوفناوری علوم محیط زیست شیمی زیست محیطی
چکیده انگلیسی
Household sand filters are used in rural areas of Vietnam to remove As, Fe, and Mn from groundwater for drinking water purposes. Currently, it is unknown what role microbial processes play in mineral oxide formation and As removal during water filtration. We performed most probable number counts to quantify the abundance of physiological groups of microorganisms capable of catalyzing Fe- and Mn-redox transformation processes in a household sand filter. We found up to 104 cells g−1 dry sand of nitrate-reducing Fe(II)-oxidizing bacteria and Fe(III)-reducing bacteria, and no microaerophilic Fe(II)-oxidizing bacteria, but up to 106 cells g−1 dry sand Mn-oxidizing bacteria. 16S rRNA gene amplicon sequencing confirmed MPN counts insofar as only low abundances of known taxa capable of performing Fe- and Mn-redox transformations were detected. Instead the microbial community on the sand filter was dominated by nitrifying microorganisms, e.g. Nitrospira, Nitrosomonadales, and an archaeal OTU affiliated to Candidatus Nitrososphaera. Quantitative PCR for Nitrospira and ammonia monooxygenase genes agreed with DNA sequencing results underlining the numerical importance of nitrifiers in the sand filter. Based on our analysis of the microbial community composition and previous studies on the solid phase chemistry of sand filters we conclude that abiotic Fe(II) oxidation processes prevail over biotic Fe(II) oxidation on the filter. Yet, Mn-oxidizing bacteria play an important role for Mn(II) oxidation and Mn(III/IV) oxide precipitation in a distinct layer of the sand filter. The formation of Mn(III/IV) oxides contributes to abiotic As(III) oxidation and immobilization of As(V) by sorption to Fe(III) (oxyhydr)oxides.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Chemosphere - Volume 138, November 2015, Pages 47-59
نویسندگان
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