Humic acid promotes arsenopyrite bio-oxidation and arsenic immobilization
Humic acid promotes arsenopyrite bio-oxidation and arsenic immobilization
复制标题
腐植酸促进毒砂生物氧化和砷固定化
DOI：
10.1016/j.jhazmat.2019.121359
复制
发表时间：
2020
影响因子：
13.6
通讯作者：
Yang Hong-ying
中科院分区：
文献类型：
--
作者：
Zhang Duo-rui;Chen Hong-rui;Xia Jin-lan;Nie Zhen-yuan;Fan Xiao-lu;Liu Hong-chang;Zheng Lei;Zhang Li-juan;Yang Hong-ying
砷黄铁矿是世界上最严重的砷污染源，其生物氧化溶解过程可由有机物介导，但相关研究较少。研究了腐殖酸（HA）存在下氧化热硫化硫杆菌（Sulfobacillus thermosulfidooxidans）对毒砂的生物氧化溶解和砷的固定化作用。矿物溶解监测通过分析的参数在溶液中，相和元素形态的矿物表面上的转换，砷固定在细胞和黄钾铁矾-HA的表面。结果表明，HA的存在促进了毒砂的溶解，生物氧化12天后，残渣中的毒砂含量为7.1%，而不加HA时的毒砂含量为19.3%。同时，HA的存在导致As和Fe的去向发生变化，而元素硫（S0）和砷酸铁在矿物表面没有积累。此外，微生物细胞和黄钾铁矾表面均形成絮状多孔结构，大量砷被吸附在其上。这些结果清楚地表明，HA可以同时促进毒砂的溶解和砷的固定，这可能是重要的含砷黄铁矿污染场地的生物淋滤。
The bio-oxidative dissolution of arsenopyrite, the most severe arsenic contamination source, can be mediated by organic substances, but pertinent studies on this subject are scarce. In this study, the bio-oxidative dissolution of arsenopyrite bySulfobacillus thermosulfidooxidansand arsenic immobilization were evaluated in the presence of humic acid (HA). The mineral dissolution was monitored through analyses of the parameters in solution, phase and element speciation transformations on the mineral surface, and arsenic immobilization on the surfaces of cells and jarosites-HA. The results show that the presence of HA enhances the dissolution of arsenopyrite, e.g., 7.1% of arsenopyrite was in the residue after 12 d of bio-oxidation compared to 19.3% in the absence of HA. Meanwhile, the presence of HA led to changes of the fates of As and Fe and no accumulation of elemental sulfur (S0) or ferric arsenate on the mineral surface. Moreover, a flocculent porous structure was formed on the surfaces of both microbial cells and jarosites, on which a large amount of arsenic was adsorbed. These results clearly indicate that HA can simultaneously promote the dissolution of arsenopyrite and arsenic immobilization, which may be significant for bioleaching of arsenopyrite-bearing contaminated sites.