Concise updates on micro-/nanoplastic detection and decontamination: Focus on magnetic biochars as remediation material

Micro- and nanoscale plastic pollution elimination from aqueous media became a critical exercise to guarantee water quality and environmental security on a global level. To ensure this, the first step is to analyze them which is only possible by the potential identification methods which were discussed in this review. Additionally, there is a growing demand for effective methods that effectively eliminate micro-/nanoplastics from contaminated water. Currently, several methods are available, including filtration, advanced oxidation process, thermal degradation, and microbial degradation which were discussed in the report. However, these methods are expensive, have low efficiency, and generate secondary pollutants. To effectively manage these issues, efficient biochars development from waste materials is a sustainable step, and further, the prospects of developing magnetic biochars raised its practical utility. Studies revealed that the dispersion of magnetic species such as Fe₃O₄, Fe(NO₃)₃, and FeCl₃ into the carbonaceous matrix enhances the surface area, catalytic properties, and magnetic activity. These property alterations lead to better adsorption capacity and facilitate their easy separation from aquatic media because of various interactional mechanisms involved. Further, this review is an extensive compilation of the production of magnetic biochar by various methods like co-precipitation, pyrolysis, hydrothermal, and chemical reduction and their decontamination performances towards wastewater containing micro-/nanoplastics. Finally, the prospects of future developments in the field of magnetic biochar adsorption technology are revealed.