https://scholars.lib.ntu.edu.tw/handle/123456789/606038
標題: | Mobilization, Methylation, and Demethylation of Mercury in a Paddy Soil under Systematic Redox Changes | 作者: | Wang J Shaheen S.M Jing M Anderson C.W.N Swertz A.-C SHAN-LI WANG Feng X Rinklebe J. |
關鍵字: | biogeochemical cycle;Hg (de-)methylation process;mercury redox chemistry;risk management;Alkylation;Colloids;Mercury compounds;Methylation;Redox reactions;Soil pollution;Clostridium spp;Contaminated soils;Desulfitobacterium;Environmental issues;Fe (oxyhydr)oxides;Oxidation reduction potential;Reductive dissolution;Relative abundance;Bacteria;carboxylic acid;ferric hydroxide;mercury;sulfate;methylmercury derivative;agricultural soil;degradation;mercury (element);methylation;mobilization;paddy field;redox conditions;soil remediation;acidification;adsorption;Article;Bacillus;carbon source;Clostridium;colloid;comparative study;demethylation;dissolution;immobilization;microbial activity;microbial community;microcosm;nonhuman;pH;reduction (chemistry);soil;soil microflora;soil pollution;total organic carbon;environmental monitoring;Oryza;oxidation reduction reaction;soil pollutant;Demethylation;Environmental Monitoring;Mercury;Methylmercury Compounds;Oxidation-Reduction;Soil;Soil Pollutants | 公開日期: | 2021 | 卷: | 55 | 期: | 14 | 起(迄)頁: | 10133-10141 | 來源出版物: | Environmental Science and Technology | 摘要: | Methylmercury (MeHg) contamination in paddy fields is a significant environmental issue globally since over half of the population of our planet consumes rice. MeHg is a neurotoxin produced by microorganisms in oxygen-limited environments. Microbial effect on MeHg production is a hotspot of research; however, it has been largely ignored how the oxidation-reduction potential (Eh) shapes MeHg formation. Here, we elucidated Hg (de)-methylation in a contaminated soil by increasing Eh stepwise from -300 to +300 mV using a sophisticated biogeochemical microcosm. At the Eh range from -300 to -100 mV, high MeHg concentration and dissolved total Hg (THg) concentration were found due to a high relative abundance of Hg-methylation bacteria (e.g., Desulfitobacterium spp.), acidification, and reductive dissolution of Fe(oxyhydr)oxides. At the Eh range from 0 to +200 mV, the formation of colloids leads to adsorption of Hg and as a result colloidal Hg increased. MeHg reduction with Eh (-300 to +200 mV) increase was mainly attributed to a reduced Hg methylation, as dissolved THg and relative abundance of Desulfitobacterium spp. decreased by 50 and 96%, respectively, at Eh of +200 mV as compared to Eh of -300 mV. Mercury demethylation might be less important since the relative abundance of demethylation bacteria (Clostridium spp.) also decreased over 93% at Eh of +200 mV. These new results are crucial for predicting Hg risks in paddy fields. ? 2021 American Chemical Society. |
URI: | https://www.scopus.com/inward/record.uri?eid=2-s2.0-85110966837&doi=10.1021%2facs.est.0c07321&partnerID=40&md5=316c7a95b5b84e3cb36a098e9e106c39 https://scholars.lib.ntu.edu.tw/handle/123456789/606038 |
ISSN: | 0013936X | DOI: | 10.1021/acs.est.0c07321 |
顯示於: | 農業化學系 |
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