Biochar Produced from Organic Waste Digestate and Its Potential Utilization for Soil Remediation: An Overview

Contamination of metal(loid)s and organic pollutants in soils has caused detrimental effects to the environment, so that there is a need to develop appropriate treatment approaches to resolve the soil pollution. In recent years, biochar produced from biowaste material has been widely used as a potential adsorbent in remediating organic and inorganic pollutants in soils. This review aims to overview the production technologies and characterization of biochars derived from sewage sludge digestate (SSD) and the organic fraction of municipal solid waste digestate (OFMSWD) and their applications for soil treatment. Critical discussions on the sorption mechanism, important factors in!uencing contaminant retention in soils, bioavailability of trace elements with biochar addition, and potential effects of biochar application to soils are summarized. The interaction mechanisms involved between the SSD and OFMSWD-derived biochars and contaminants, the main factors in!uencing the biochars’ sorption ef"ciency and possible effects to the environment are discussed in this review.