Food waste biochar: a sustainable solution for agriculture application and soil–water remediation

Biochar is a promising pyrolysed carbon-enriched soil amendment and has excellent properties for agriculture production and to remediate environmental pollution. A set of reviews were conducted on biochar production by pyrolysis process from various waste biomass which has drawn extensive interest due to the low cost of production with several benefits. As many potential technologies have been developed, there are still several knowledge gaps that have been identified for some key points to contribute a comprehensive study towards soil fertility, nutrient and water retention, soil microbial activity, plant growth and yield, pollution remediation, mitigation of greenhouse gas emission and an improvement in the farmer’s economy to achieve maximum profit by adopting environmentally friendly technique “pyrolysis”. Therefore, this review explored a detailed study on food waste biochar production by the pyrolysis process and its impact on different applications as an amendment. Slow pyrolysis process at low and medium temperatures is a potential amendment for agriculture production and soil and water remediation by enhancing biochar properties like carbon, BET surface area, cation exchange capacity, zeta potential, and nutrient content, etc. with minimum ash content. The biochar enhances soil water and nutrient retention capacity, crop yield, and improved microbial community at different soil quality. Additionally, food waste to biochar is a realistic adsorbent and economical carbon sequester to mitigate GHG emissions. This review conducted a brief assessment of the knowledge gaps and future research directions for researchers, encouraging investigators, stakeholders, and policymakers to make the best possible decision for food waste valorization.