Application of biochar for soil remediation

Research into the use of biochar for the remediation of contaminated soils has expanded rapidly over the past 5 yr. We review recent developments in the field and present the findings emanating from small-scale batch sorption experiments, through soil incubations and bioassays, to large-scale field experiments. We discuss the evidence that these experiments have contributed toward a mechanistic understanding of how biochar is capable of remediating soils contaminated with both organic and inorganic contaminants. The effects of biochar pyrolysis temperature, biochar source material, soil type, and contaminant type on the performance of biochars for remediation are identified. The risks associated with applying biochar to uncontaminated agricultural soils are discussed. Knowledge gaps and questions are identified which, if addressed, will considerably advance the application of biochar as a soil remediation tool in the future.