Abstract

Biochar, or called black carbon, is a promising remedial material for contaminated land due to its multiple additional benefits such as carbon storage, reuse of agricultural wastes, greening etc. Before a large-scale application, it is crucial to understand the interaction between biochar and contaminants as well as its performance in contaminated soils. In this study, Salisbury biochar, derived from British hardwood, was applied to a sandy made-ground contaminated land and an artificially contaminated clay soil respectively. The performance and mechanism of Salisbury biochar in immobilising heavy metals in the two soils were investigated. In order for a further understanding of the interaction between biochar and heavy metals to aid its potential application in soil remediation, the characteristics and mechanism of heavy metal adsorption on a range of biochars (including Salisbury biochar) were investigated in water. This study aimed at providing a deeper understanding of the biochar impact on the mobility and speciation of heavy metals in soils as well as the biochar adsorption of heavy metals in water, and aiding its future application in soil remediation.