Key Laboratory for Water Quality and Conservation of the Pearl River Delta, Ministry of Education, School of Environmental Science and Engineering, Guangzhou University, Guangzhou 510006, China.
Key Laboratory for Water Quality and Conservation of the Pearl River Delta, Ministry of Education, School of Environmental Science and Engineering, Guangzhou University, Guangzhou 510006, China; State Key Laboratory of Geohazard Prevention and Geoenvironment Protection, Chengdu University of Technology, Chengdu 610059, China.
Sci Total Environ. 2022 Apr 20;818:151826. doi: 10.1016/j.scitotenv.2021.151826. Epub 2021 Nov 22.
Mining activities lead to elevated levels of antimony (Sb) and arsenic (As) in river systems, having adverse effects on the aquatic environment and human health. Microbes inhabiting river sediment can mediate the transformation of Sb and As, thus changing the toxicity and mobility of Sb and As. Compared to river sediments, natural wetlands could introduce distinct geochemical conditions, leading to the formation of different sedimentary microbial compositions between river sediments and wetland sediments. However, whether such changes in microbial composition could influence the microbially mediated geochemical behavior of Sb or As remains poorly understood. In this study, we collected samples from a river contaminated by Sb tailings and a downstream natural wetland to study the influence of microorganisms on the geochemical behavior of Sb and As after the Sb/As-contaminated river entered the natural wetland. We found that the microbial compositions in the natural wetland soil differed from those in the river sediment. The Sb/As contaminant components (Sb(III), As(III), As(V), As) and nutrients (TC) were important determinants of the difference in the compositions of the microbial communities in the two environments. Taxonomic groups were differentially enriched between the river sediment and wetland soil. For example, the taxonomic groups Xanthomonadales, Clostridiales and Desulfuromonadales were important in the wetland and were likely to involve in Sb/As reduction, sulfate reduction and Fe(III) reduction, whereas Burkholderiales, Desulfobacterales, Hydrogenophilales and Rhodocyclales were important taxonomic groups in the river sediments and were reported to involve in Sb/As oxidation and sulfide oxidation. Our results suggest that microorganisms in both river sediments and natural wetlands can affect the geochemical behavior of Sb/As, but the mechanisms of action are different.
采矿活动导致河流系统中锑（Sb）和砷（As）含量升高，对水生环境和人类健康产生不利影响。栖息在河底沉积物中的微生物可以介导 Sb 和 As 的转化，从而改变 Sb 和 As 的毒性和迁移性。与河底沉积物相比，自然湿地可能会引入不同的地球化学条件，导致河底沉积物和湿地沉积物之间形成不同的沉积微生物组成。然而，微生物组成的这种变化是否会影响 Sb 或 As 的微生物介导的地球化学行为仍知之甚少。在这项研究中，我们从受 Sb 尾矿污染的河流和下游自然湿地中采集了样品，以研究 Sb/As 污染河流进入自然湿地后，微生物对 Sb 和 As 地球化学行为的影响。我们发现，自然湿地土壤中的微生物组成与河底沉积物中的微生物组成不同。Sb/As 污染物成分（Sb(III)、As(III)、As(V)、As）和营养物质（TC）是两种环境中微生物群落组成差异的重要决定因素。分类群在河底沉积物和湿地土壤之间存在差异富集。例如，黄单胞菌目、梭菌目和脱硫单胞菌目在湿地中很重要，可能涉及 Sb/As 还原、硫酸盐还原和 Fe(III)还原，而伯克霍尔德氏菌目、脱硫杆菌目、氢噬菌目和红环菌目是河底沉积物中的重要分类群，据报道，它们涉及 Sb/As 氧化和硫化物氧化。我们的结果表明，河底沉积物和自然湿地中的微生物都可以影响 Sb/As 的地球化学行为，但作用机制不同。
