Effects of microplastics on soil ecosystems and remediation technologies

Due to agricultural film fragmentation, sewage irrigation and other anthropogenic activities, the content and abundance of microplastics in soil are gradually surpassing those in the ocean, and becoming one of the main pollution sources of soil. Soil organisms can absorb soil microplastics, among which microplastics in food crops can enter the human body through the food chain, causing the risk of human microplastic exposure. In addition, soil microplastics can also directly cause toxicity to soil. The sources, migration and other environmental behavior of microplastics in soil ecosystem were summarized, and the impact of microplastics on soil ecosystem was emphasized. The results mainly include the following aspects: (1) Microplastics can migrate and transport in the soil environmental system through the space between soil particles, the root cracks of plants and the movement of animals. (2) Microplastics can affect soil physical and chemical properties, plant growth and development, animal behavior and microbial diversity. (3) Microorganisms and enzymes can degrade microplastics in the soil environment and directly reduce microplastics in the soil system, while biochar can reduce the toxicity of microplastics to the soil ecosystem. All three are potential options for soil microplastics remediation technologies. Finally, the possible research direction of soil microplastics in the future was proposed, in order to provide guidance for the pollution control of soil microplastics.