Application of biochar-based materials for remediation of arsenic contaminated soil and water: Preparation, modification, and mechanisms

Effective purification of arsenic (As)-contaminated soil and water remains an urgent task for mankind. Biochar was applied to remove As due to its low price, easy preparation, and high efficiency. This paper provides the latest analysis of biochar-based materials for arsenic-contaminated water and soil. In this review, different sources of feedstock and modification methods on the performance of biochar and the adsorption capacity of As are compared. The factors such as pH, site conditions, and the coexistence of heavy metals affecting biochar-based materials in arsenic removal are also studied. The As removal mechanisms were mainly inner-complexation/precipitation, ligand exchange, electrostatic attraction, and redox transformation. Finally, this review proposes insights on future development and challenges of biochar, along with the cost, regeneration, and practical application analysis. Results showed that biochar-based materials could be applied for practical applications. [Display omitted] •Biochar has great potential in the polluted soil and water remediation.•Biochar-based materials in As-contaminated environment remediation was summarized.•Biochar-based materials are widely available and effective for the adsorption of As.•Insights on future development and challenges of biochar application was proposed.