Influence of dissolved organic matter on methylmercury transformation during aerobic composting of municipal sewage sludge under different C/N ratios  

作　　者：Xin Zheng Jing Wang Chuanbing Zhang Yong Zhang Doudou Huang Shuxiao Yan Tengfei Sun Yuxiang Mao Yong Cai 

机构地区：[1]School of Resources&Environment,Henan Polytechnic University,Jiaozuo 454000,China [2]School of Environment and Health,Jianghan University,Wuhan 430056,China [3]Huaxia Besince Environmental Technology Co.Ltd.,Zhengzhou 450008,China [4]Department of Chemistry and Biochemistry&Southeast Environmental Research Center,Florida International University,Miami,FL 33199,USA

出　　处：《Journal of Environmental Sciences》2022年第9期130-138,共9页环境科学学报（英文版）

基　　金：supported by the National Natural Science Foundation of China (No. 21605060 );the Key Scientific Research Project of Colleges and Universities in Henan Province (No. 20A610006 )。

摘　　要：Current knowledge about the transformation of total mercury and methylmercury(Me Hg) in aerobic composting process is limited. In this study, the composition and transformation of mercury and dissovled organic matter(DOM) in aerobic composting process of municipal sewage sludge were were comprehensively characterized, and the differences among the three C/N ratio(20, 26 and 30) were investigated. The main form of mercury in C/N 20 and 26 was organo-chelated Hg(F3, 46%-60%);while the main form of mercury in C/N 30 was mercuric sulfide(F5, 64%-70%). The main component of DOM in C/N 20 and 26 were tyrosine-like substance(C1, 53%-76%) while the main fractions in C/N 30 were tyrosine-like substance(C1, 28%-37%) and fulvic-like substance(C2, 17%-39%). The mercury and DOM varied significantly during the 9 days composting process. Compared to C/N 20 and 26, C/N 30 produced the less Me Hg after aerobic composting process, with values of 658%(C/N 20), 1400%(C/N 26) and 139%(C/N 30) of the initial, respectively. Meanwhile, C/N 30 produced the best compost showed greater degree of DOM molecular condensation and humification. Hg fraction had been altered by DOM, as indicated by a significant correlation between mercury species and DOM components. Notably, C/N 30 should be used as an appropriate C/N ratio to control the methylation processes of mercury and degration of DOM.

关 键 词：METHYLMERCURY Dissolved organic matter Municipal sewage sludge Aerobic composting C/N ratio 

分 类 号：S141.4[农业科学—肥料学] X703[农业科学—农业基础科学]