Institute of Soil and Water Resources and Environmental Science, College of Environmental and Resource Sciences, Zhejiang Provincial Key Laboratory of Agricultural Resources and Environment, Zhejiang University, Hangzhou 310058, China.
School of Chemistry, Environmental & Life Sciences, University of The Bahamas, New Providence, Nassau, The Bahamas.
J Hazard Mater. 2021 Jun 5;411:125123. doi: 10.1016/j.jhazmat.2021.125123. Epub 2021 Jan 13.
Biochar is widely used as an amendment to optimize the composting process. In this study, we firstly investigated the effects of biochar amendment on methylation and volatilization of arsenic (As), and the microbial communities during manure composting. Biochar amendment was found to increase the concentrations of monomethylarsonic acid (MMA) and dimethylarsinic acid (DMA) during mesophilic (days 0-10) and early thermophilic (days 11-15) phases, and promote As volatilization during the maturing phase (days 60-80) of composting. In addition, the abundances of As(V) reductase (arsC) and As(III) S-adenosyl-L-methionine methyltransferase (arsM) genes were higher in the biochar treatment than that in the control. Moreover, biochar amendment influenced the microbial communities by promoting As methylation and volatilization via Ensifer and Sphingobium carrying arsC genes, and Rhodopseudomonas and Pseudomonas carrying arsM genes. This study emphasized the considerable role of biochar on methylation and volatilization of As during manure composting and provided an overall characterization of the community compositions of arsC and arsM genes during manure composting. It will broaden our insights in As biogeochemical cycle during manure composting with biochar amendment, which will facilitate the regulation of As during manure composting and its application in agricultural soil.
生物炭广泛用作改良剂以优化堆肥过程。在本研究中，我们首先研究了生物炭改良对粪便堆肥过程中砷的甲基化和挥发以及微生物群落的影响。生物炭改良被发现会在中温（第 0-10 天）和早期高温（第 11-15 天）阶段增加一甲基砷酸（MMA）和二甲基砷酸（DMA）的浓度，并在堆肥的成熟阶段（第 60-80 天）促进砷挥发。此外，生物炭处理中砷（V）还原酶（arsC）和砷（III）S-腺苷-L-蛋氨酸甲基转移酶（arsM）基因的丰度高于对照组。此外，生物炭改良通过携带 arsC 基因的根瘤菌和鞘氨醇单胞菌促进砷甲基化和挥发，以及携带 arsM 基因的红假单胞菌和假单胞菌来影响微生物群落。本研究强调了生物炭在粪便堆肥过程中对砷甲基化和挥发的重要作用，并全面描述了粪便堆肥过程中 arsC 和 arsM 基因的群落组成。这将拓宽我们对生物炭改良粪便堆肥过程中砷生物地球化学循环的认识，有助于调节粪便堆肥过程中的砷及其在农业土壤中的应用。
