Recent developments in biochar utilization as an additive in organic solid waste composting: A review.

In recent years, considerable studies have been devoted to investigating the effect of biochar application on organic solid waste composting. This review provides an up-to-date overview of biochar amendment on composting processes and compost quality. Biochar production, characteristics, and its application coupled with the basic concepts of composting are briefly introduced before detailing the effects of biochar addition on composting. According to recent studies, biochar has exhibited great potential for enhancing composting. It is evident that biochar addition in composting can: (1) improve compost mixture physicochemical properties, (2) enhance microbial activities and promote organic matter decomposition, (3) reduce ammonia (NH3) and greenhouse gas (GHG) emissions, and (4) upgrade compost quality by increasing the total/available nutrient content, enhancing maturity, and decreasing phytotoxicity. Despite that, further research is needed to explore the mechanism of biochar addition on composting and to evaluate the agricultural and environmental performances of co-composted biochar compost.