生物合成Bio-MnO_(x)对砷污染土壤的稳定化效果分析

STABILIZATION OF ARSENIC IN CONTAMINATED SOILS USING BIOLOGICAL Mn OXIDE(Bio-MnO_(x))

通过室内模拟实验,研究了生物合成锰氧化物(Bio-MnO_(x))材料对污染土壤中砷(As)的稳定化效果。结果表明:1)Bio-MnO_(x)的加入能够有效降低砷的浸出量,其中水溶性砷含量由2.28 mg/kg降至0.86 mg/kg,减少62.3%;2)五步连续法浸提结果发现,Bio-MnO_(x)处理后水溶态砷和表面吸附态砷的相对含量显著降低;3)风险分析进一步表明Bio-MnO_(x)处理后砷的环境风险降低;4)基于细菌16s RNA生物多样性分析表明,经过Bio-MnO_(x)处理后,土壤微生物多样性的丰富度显著增加;5)微生物群落结构分析发现,土壤微生物群落结构发生明显演替,属水平下的细菌结构由芽孢杆菌属向梭状芽孢菌属、丛毛单胞菌属、敏感梭菌属等转变。总体而言,Bio-MnO_(x)是一种比较有效的修复砷污染土壤的生物材料。

Through indoor simulation experiments,the effect of biosynthetic manganese oxide(Bio-MnO_(x))material on the stabilization of arsenic(As)in contaminated soil was studied.The results showed that:1)the addition of Bio-MnO_(x)could effectively decrease the leaching amount of As,in which the water-soluble As content decreased from 2.28 mg/kg to 0.86 mg/kg,with a reduction efficiency of 62.3%;2)the five-step continuous extraction results showed that the content of water-soluble As and surface-adsorbed fraction decreased significantly after Bio-MnO_(x)treatment;3)the environmental risk analysis further confirmed that the risk of As decreased significantly after Bio-MnO_(x)treatment;4)bacterial biodiversity analysis based on 16 s RNA indicated that the richness of soil microbial diversity increased significantly after Bio-MnO_(x)treatment;5)the analysis of microbial community structure showed that the dominant bacterial community structure changed from Bacillus to Clostridium,Comamonas,and Clostridium sensu tricto at the genus level.In general,Bio-MnO_(x)could be used as an effective biogenic material to stabilize As in soils.