硫代硫酸盐影响地下水环境中砷(As)和铁(Fe)的生物还原和迁移转化。这项研究的目的是研究微生物介导的硫循环对As和Fe的生物还原和相互作用的影响。进行了微观世界实验,包括硫代硫酸盐的生物还原,如(V),和柠檬酸杆菌属的Fe(III)。JH012-1,以及在不同初始砷酸盐浓度下输入的硫代硫酸盐对As(V)和Fe(III)生物还原的影响。结果表明柠檬酸杆菌属。JH012-1对硫代硫酸盐表现出强大的还原能力,如(V),和Fe(III)。提高硫代硫酸盐水平促进了Fe(III)和As(V)的生物还原。当添加0、0.1、0.5和1mM硫代硫酸盐时,Fe(III)在9天内完全还原,3天,1天,0.5天,同时,72.8%,82.2%,85.5%,并减少了90.0%的As(V),分别。As(III)与硫化物结合的产物受As-S的比例控制。当初始砷酸盐浓度为0.025mM时,硫代硫酸盐的添加导致可溶性硫代亚砷酸盐的积累。然而,当初始砷酸盐水平增加到1mM时,形成了雄黄或雄黄的沉淀物。在砷和铁同时存在的情况下,As(V)显著抑制Fe(III)的生物还原。在0、0.025和1mMAs(V)的浓度下,Fe(III)的还原率为100%,91%,83%,分别。在这种情况下,硫代硫酸盐还原产生的硫化物倾向于与Fe(II)而不是As(III)结合。因此,研究硫代硫酸盐对地下水中砷和铁迁移转化的影响,应考虑砷-铁和硫代硫酸盐浓度的竞争。
Thiosulfate influences the bioreduction and migration transformation of arsenic (As) and iron (Fe) in groundwater environments. The aim of this study was to investigate the impact of microbially-mediated sulfur cycling on the bioreduction and interaction of As and Fe. Microcosm experiments were conducted, including bioreduction of thiosulfate, As(V), and Fe(III) by Citrobacter sp. JH012-1, as well as the influence of
thiosulfate input at different initial arsenate concentrations on the bioreduction of As(V) and Fe(III). The results demonstrate that Citrobacter sp. JH012-1 exhibited strong reduction capabilities for
thiosulfate, As(V), and Fe(III). Improving
thiosulfate level promoted the bioreduction of Fe(III) and As(V). When 0, 0.1, 0.5, and 1 mM thiosulfate were added, Fe(III) was completely reduced within 9 days, 3 days, 1 day, and 0.5 days, simultaneously, 72.8%, 82.2%, 85.5%, and 90.0% of As(V) were reduced, respectively. The products of As(III) binding with sulfide are controlled by the ratio of As-S. When the initial arsenate concentration was 0.025 mM, the addition of thiosulfate resulted in the accumulation of soluble thioarsenite. However, when the initial arsenate level increased to 1 mM, precipitates of orpiment or realgar were formed. In the presence of both arsenic and iron, As(V) significantly inhibits the bioreduction of Fe(III). Under the concentrations of 0, 0.025, and 1 mM As(V), the reduction rates of Fe(III) were 100%, 91%, and 83%, respectively. In this scenario, the sulfide produced by thiosulfate reduction tends to bind with Fe(II) rather than As(III). Therefore, the competition of arsenic-iron and thiosulfate concentration should be considered to study the impact of
thiosulfate on arsenic and iron migration and transformation in groundwater.