Agro-Environmental Protection Institute, Ministry of Agriculture and Rural Affairs/Key Laboratory of Original Agro-Environmental Pollution Prevention and Control, MARA/Tianjin Key Laboratory of Agro-Environment and Agro-Product Safety, Tianjin 300191, China.
College of Science, Huazhong Agricultural University, Wuhan 430070, China.
J Hazard Mater. 2023 Oct 15;460:132313. doi: 10.1016/j.jhazmat.2023.132313. Epub 2023 Aug 15.
The degradation of organic pollutants and the adsorption of organic pollutants onto microplastics (MPs) in the environment have recently been intensively studied, but the effects of biocurrents, which are widespread in various soil environments, on the environmental behavior of MPs and antibiotic pollutants have not been reported. In this study, it was found that polylactic acid (PLA) and polyvinyl chloride (PVC) MPs accelerated the mineralization of humic substances in microbial electrochemical systems (MESs). After tetracycline (TC) was introduced into the MESs, the internal resistance of the soil MESs decreased. Additionally, the presence of MPs enhanced the charge output of the soil MESs by 40% (PLA+TC) and 18% (PVC+TC) compared with a control group without MPs (424 C). The loss in MP mass decreased after TC was added, suggesting a promotion of TC degradation rather than MP degradation for charge output. MPs altered the distribution of the highest occupied molecular orbitals and lowest unoccupied molecular orbitals of TC molecules and reduced the energy barrier for the TC hydrolysis reaction. The microbial community of the plastisphere exhibited a greater ability to degrade xenobiotics than the soil microbial community, indicating that MPs were hotspots for TC degradation. This study provides the first glimpse into the influence of MPs on the degradation of TC in MESs, laying a theoretical and methodological foundation for the systematic evaluation of the potential risks of environmental pollutants in the future.
近年来，人们对环境中有机污染物的降解和微塑料（MPs）对有机污染物的吸附进行了深入研究，但生物电流对 MPs 和抗生素污染物环境行为的影响尚未见报道。本研究发现，聚乳酸（PLA）和聚氯乙烯（PVC）MPs 加速了微生物电化学系统（MESs）中腐殖质的矿化。在向 MESs 中引入四环素（TC）后，土壤 MESs 的内阻降低。此外，与没有 MPs 的对照组（424 C）相比，MPs 的存在使土壤 MESs 的电荷输出增加了 40%（PLA+TC）和 18%（PVC+TC）。添加 TC 后 MP 质量损失减少，表明电荷输出促进了 TC 的降解而不是 MP 的降解。MPs 改变了 TC 分子的最高占据分子轨道和最低未占据分子轨道的分布，并降低了 TC 水解反应的能垒。塑料区的微生物群落比土壤微生物群落具有更强的降解外来化合物的能力，表明 MPs 是 TC 降解的热点。本研究首次揭示了 MPs 对 MESs 中 TC 降解的影响，为未来系统评估环境污染物潜在风险奠定了理论和方法基础。
