ABSTRACT
Contamination of soil, sediment and groundwater systems with arsenic (As) represents a global environmental, agricultural and public health issue due to the potentially toxic nature of As to different life forms. In recent years, biochar has seen considerable attention for the remediation and restoration of As-contaminated soils, which depends upon the feedstock type, soil physical, chemical and biological properties, as well as on different As species in soil. This review briefly covers different biochar production methods; advances our understanding on the impact of biochar for immobilization/mobilization of As in contaminated soils; discusses biochar-mediated changes in physical and chemical properties, and microbial activity of As-contaminated soils. We also describe the impact of biochar on solid-phase speciation of As in soils and how it influences As bioavailability, soil-plant transfer, and as such the biogeochemical behaviour of As in biochar amended soils.
