Risk assessment of potentially toxic elements, microplastics, and microorganisms in groundwater around municipal solid waste landfill

Risk assessment of potential toxic elements (PTEs), microplastics (MPs) and microorganisms in groundwater around landfills is critical. Waste from landfills seeps into groundwater contaminating water quality, threatening groundwater safety, and negatively affecting the ecosystem. This study explored spatial and temporal changes in PTEs, MPs, and microorganisms in the groundwater around a closed landfill. The results showed that Mn and Cr were the most predominant PTEs in the groundwater, average Mn and Cr concentrations in June being 1.16 and 4.51 times higher than in November, respectively. The Risk assessment of PTEs in groundwater Mn was heavily contaminated, Cr was moderately contaminated. The abundance of MPs the average value of MPs in June was 1.55 times higher than that in November; the MPs indicated that groundwater is more heavily contaminated, especially in the downstream areas. The Proteobacteria is the main phylum, and PLS-PM, PTEs were positively correlated with the phylum of microorganisms, negatively correlated with the genus of microorganisms and the abundance of MPs. This study emphasizes the importance of environmental management of landfills, provide new insights into the monitoring and identification of groundwater contamination as well as scientific guidance on appropriate remediation strategies for leachate-contaminated groundwater.