Biochar for the adsorptive removal of pesticide and microplastics from soil

The contamination of soils by pesticides and microplastics adversely affects soil structure, microbial communities, and soil biota, highlighting the need for environmentally sustainable remediation approaches. Biochar has received growing attention as a promising amendment for soil remediation due to its porous structure and high specific surface area. The remediation performance of biochar varies widely depending on physicochemical properties, which are influenced by several factors including feedstock type, pyrolysis conditions, and surface modification strategies. This review summarizes recent research trends in biochar-based remediation of pesticides and microplastics, identifies key factors governing remediation performance, and discusses limitations associated with current studies highlighting knowledge gaps limiting practical application. Although existing studies indicate promising remediation potential, most studies have focused on short-term batch adsorption or column experiments that do not fully reflect the complexity of co-contaminated soils and long-term stability under field conditions. Therefore, to advance biochar toward practical implementation, further efforts should include optimization of surface modification techniques, clarification of their effects on biochar properties, validation through field-scale studies, evaluation of microplastics across diverse polymer types and particle-size ranges, and quantitative assessment of interactions among co-contaminants. These efforts will be essential for developing biochar into a sustainable and effective remediation technology for soils.