微塑料对砷污染土壤中微生物群落和砷形态转化的影响

Impact of Microplastics on Microbial Communities and Arsenic Spe⁃ciation Transformation at Arsenic-contaminated Soil

微塑料广泛存在于自然环境中,并给生态系统和人类健康造成潜在的暴露风险。关于微塑料的研究多集中于水体环境,仅有较少研究报道了微塑料对土壤环境的影响。该研究讨论了两种微塑料类型(聚乙烯(PE)及聚乳酸(PLA))对砷污染的土壤微生物群落和砷形态转化的影响。结果表明,两种微塑料会提高土壤中微生物物种的丰度及多样性。相对于对照组,PLA微塑料使得土壤中生物有效态砷占比增加。两种微塑料在个别时间点影响土壤中砷还原基因的丰度,促进生物有效态五价砷还原为三价砷。该研究初步解释了微塑料对土壤中重金属产生的影响,为后续研究提供了科学参考。

Microplastics have been widely found in natural environment and may pose potential expo⁃sure risks to ecosystems and human health.Most of researches focuses on the fate of microplastics in aquatic environment,while a few studies were related to behaviors of microplastics in soil.The pres⁃ent study was conducted to examine the impacts of microplastics(polyethylene(PE)and polylactic ac⁃id(PLA))on microbial communities and arsenic transformation in arsenic-contaminated soils.Re⁃sults indicate that both types of microplastics enhanced the abundance of microbial species in the soil.Compared to control group,the proportion of bioavailable arsenic species were greater in the soil+PLA groups.Both types of microplastics would increase the arsenate gene copies in soil at 6 and 12 d,promoting the reduction of bioavailable pentavalent arsenic to trivalent arsenic.The pres⁃ent study found that microplastics could affect the proportions of bioavailable arsenic in soil,provid⁃ing data for subsequent research.