Mobilization and transformation of arsenic from ternary complex OM-Fe(III)-As(V) in the presence of As(V)-reducing bacteria
Mobilization and transformation of arsenic from ternary complex OM-Fe(III)-As(V) in the presence of As(V)-reducing bacteria
复制标题
As(V) 还原菌存在下三元复合物 OM-Fe(III)-As(V) 中砷的动员和转化
DOI：
10.1016/j.jhazmat.2019.120975
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发表时间：
2020
影响因子：
13.6
通讯作者：
Yanshan Cui
中科院分区：
文献类型：
--
作者：
Xiaolin Cai;Pengfei Wang;Zejiao Li;Yan Li;Naiyi Yin;Huili Du;Yanshan Cui
Organic matter (OM) was proved to have a high affinity for arsenic (As) in the presence of ferric iron (Fe(III)), the formed ternary complex OM-Fe(III)-As(V) were frequently studied before; however, the mobilization and transformation of As from OM-Fe(III)-As(V) in the presence of As(V)-reducing bacteria remains unclear. Two different strains (Desulfitobacteriumsp. DJ-3,Exiguobacteriumsp. DJ-4) were incubated with OM-Fe(III)-As(V) to assess the biotransformation of As and Fe. Results showed thatDesulfitobacteriumsp. DJ-3 could substantially stimulate the reduction and release of OM-Fe complexed As(V) and resulted in notable As(III) release (30 mg/L). The linear combination fitting result ofk3-weighted As K-edge EXAFS spectra showed that 56% of OM-Fe-As(V) was transformed to OM-Fe-As(III) after 144 h. Besides, strain DJ-3 could also reduce OM complexed Fe(III), which lead to the decomposition of ternary complex and the release of 11.8 mg/g Fe(II), this microbial Fe(III) reduction process has resulted in 11% more As liberation from OM-Fe(III)-As(V) than without bacteria. In contrast,Exiguobacteriumsp. DJ-4 could only reduce free As(V) but cannot stimulate As release from the complex. Our study provides the first evidence for microbial As reduction and release from ternary complex OM-Fe(III)-As(V), which could be of great importance in As geochemical circulation.
