Effect of different biomass species and pyrolysis temperatures on heavy metal adsorption, stability and economy of biochar

Biochar has great potential for the remediation of heavy metal pollution, but the adsorption instability and high cost of long-term soil remediation limit its industrial application. In this study, three common agricultural wastes were used to prepare biochar at temperatures ranging from 300 degrees to 600 degrees C and the correlative mechanisms among the preparation process, physicochemical characteristics, cost, adsorption properties, and stability of biochar were systematically studied. The results illustrated that with increasing pyrolysis temperature, the biochar yield decreased, whereas the stability and adsorption capacity increased. Economic analyses showed that biochar prepared from rice husks at 500 degrees C had the highest economic value (292.73 mg/$ for Pb2+, 84.29 mg/$ for Cu2+). In addition, biochar prepared using rice husk had the highest adsorption stability due to the dominance of complexation and ion exchange. The comprehensive analysis conducted in this study provides an evaluation of the biochar preparation process and its industrial applications.

Automated summary

This study investigated the preparation process, physicochemical characteristics, cost, adsorption properties, and stability of biochar prepared from agricultural wastes. The results showed that the stability and adsorption capacity of biochar increased with increasing pyrolysis temperature. Biochar prepared from rice husks exhibited the highest adsorption stability and economic value.