Effect of natural aging on biochar physicochemical property and mobility of Cd (II)

Abstract

This project utilized both field experiment and laboratory analysis to address the lack of understanding of the alterations in properties and functions of biochar, as well as the impact of heavy metal passivation in soil over long-term natural field aging. The study aimed to examine the changes in the physical and chemical characteristics of biochar over an extended period of natural aging. Additionally, it aimed to analyze the impact and mechanism of biochar on the reduction of the harmful effects of the heavy metal cadmium (Cd) during the aging process. Both original and aged biochar fitted to the pseudo-second-order kinetics model and the Langmuir model. The aging process increased the adsorption of Cd by biochar and decreased the leaching of Cd²⁺. This provided a scientific basis for evaluating biochar's environmental behavior and its potential for use in the remediation of soil contaminated with heavy metals.