Review of Biochar Properties and Remediation of Metal Pollution of Water and Soil

BACKGROUND: Mining, waste disposal, and agrochemical residues have contributed to pollution of water and soil with toxic metals in most low- and middle-income countries, raising concerns of ecological safety and public health. This has prompted many studies into the production and utilization of biochars to adsorb toxic metal contaminants from soil and water. OBJECTIVE: The present study presents a review of biochar properties, the mechanisms of toxic metal adsorption onto biochar, and sorption of toxic metal contaminants in water and soil in small scale applications and laboratory experiments. METHODS: A total of 305 articles were collected, and after screening for relevance, a final of 164 articles from both high- and low- and middle-income countries were used in this review paper. DISCUSSION: Biochar for sorption has proven effective and its raw materials are readily available, cost effective, environmentally stable and a good form of waste management. CONCLUSIONS: Different techniques of biochar production influence the properties of biochar and adsorption of toxic metals from water and soil. COMPETING INTERESTS: The authors declare no competing financial interests.