Applications of biochar in the remediation of soil microplastic pollution: A review

Microplastics (MPs), recognized as an emerging pollutant, represent a significant threat to terrestrial ecosystems worldwide by compromising soil structure, inhibiting plant growth and the reproduction of soil fauna, and disrupting biogeochemical cycles. The remediation of MP-contaminated soils is essential for sustaining healthy soil, ensuring global food security, and mitigating climate change. This review provides a comprehensive analysis of the current research advancements regarding biochar (BC) as a sustainable approach for the remediation of MP-contaminated soils. BC, an environmentally benign material with multifunctional properties, has been shown to enhance soil characteristics in MP-affected environments by stabilizing soil aggregates, improving porosity and moisture retention, and regulating pH and nutrient levels. The review illustrates that BC promote microbial diversity, increases populations of beneficial bacteria, and creates a favorable environment for the growth and reproduction of plants and soil animals in MP-contaminated soils. The efficacy of BC remediation is influenced by its physicochemical properties (such as surface area, porosity, and functional groups) as well as the specific conditions of the soil (including texture, organic matter content, and pH). This comprehensive evaluation underscores BC as a promising, cost-effective, and environmentally sustainable strategy for the remediation of MP-contaminated soils, bearing significant implications for agricultural sustainability and ecosystem health. However, knowledge gaps persist in the understanding of microscopic interactions between BC and MPs, as well as in the application of BC at the field scale. These gaps should inform and direct future research endeavors.