Rethinking anaerobic As(III) oxidation in filters: Effect of indigenous nitrate respirers
Rethinking anaerobic As(III) oxidation in filters: Effect of indigenous nitrate respirers
复制标题
重新思考过滤器中的厌氧 As(III) 氧化：本土硝酸盐呼吸器的影响
DOI：
10.1016/j.chemosphere.2017.12.158
复制
发表时间：
2017
期刊：
影响因子：
8.8
通讯作者：
Chuanyong Jing
中科院分区：
文献类型：
--
作者：
Jinli Cui;Jingjing Du;Haixia Tian;Tingshan Chan;Chuanyong Jing
微生物在含水层中砷 (As) 的氧化还原转化中发挥着关键作用。在本研究中，在使用颗粒 TiO2 过滤地下水以及随后进行废 TiO2 厌氧填埋的过程中，探讨了本地细菌（尤其是普遍存在的硝酸盐呼吸器）对亚砷酸盐 (As(III)) 氧化的影响。 X 射线吸收近边结构光谱分析表明，在模拟厌氧垃圾填埋场中存在硝酸盐的情况下，As(III) 被氧化（10 天内氧化 46%）。同时，废TiO2上的铁(Fe)形态主要是无定形砷酸铁、水铁矿和针铁矿。 Fe相在厌氧垃圾填埋场培养期间没有变化。批量培养实验表明，在厌氧条件下，本土细菌以硝酸盐为末端电子受体，10天内将As(III)完全氧化为砷酸盐(As(V))。细菌群落分析表明，地下水基质中存在多种微生物种类。系统发育树分析表明，Proteobacteria是优势门，Hydrogenophaga(34%)、Limnohabitans(16%)和Simplicispira(7%)是主要细菌属。硝酸盐呼吸器，尤其是来自 Hydrogenophaga.genus 的硝酸盐呼吸器，使用硝酸盐代替氧气作为电子受体，厌氧氧化 As(III)。我们的研究表明，微生物可以利用吸附介质上的硝酸盐促进地下水砷氧化。
Microorganisms play a key role in the redox transformation of arsenic (As) in aquifers. In this study, the.impact of indigenous bacteria, especially the prevailing nitrate respirers, on arsenite (As(III)) oxidation.was explored during groundwater filtration using granular TiO2 and subsequent spent TiO2 anaerobic.landfill. X-ray absorption near edge structure spectroscopy analysis showed As(III) oxidation (46% in 10.days) in the presence of nitrate in the simulated anaerobic landfills. Meanwhile, iron (Fe) species on the.spent TiO2 were dominated by amorphous ferric arsenate, ferrihydrite and goethite. The Fe phase.showed no change during the anaerobic landfill incubation. Batch incubation experiments implied that.the indigenous bacteria completely oxidized As(III) to arsenate (As(V)) in 10 days using nitrate as the.terminal electron acceptor under anaerobic conditions. The bacterial community analysis indicated that.various kinds of microbial species exist in groundwater matrix. Phylogenetic tree analysis revealed that.Proteobacteria was the dominant phylum, with Hydrogenophaga (34%), Limnohabitans (16%), and Simplicispira (7%) as the major bacterial genera. The nitrate respirers especially from the Hydrogenophaga.genus anaerobically oxidized As(III) using nitrate as an electron acceptor instead of oxygen. Our study.implied that microbes can facilitate the groundwater As oxidation using nitrate on the adsorptive media.