Enhanced adsorption and regulation mechanism of ball milling-modified biochar on Cd and atrazine in soil.

In order to improve the adsorption and immobilization capacity of biochar for Cd and atrazine in soil, the biochar was prepared from corn straw and modified by dry ball milling under various conditions. Compared with the pristine biochar (PB), the ball-milled biochar (BB) had a larger specific surface area and more pores, the number of oxygen-containing functional groups increased significantly, and the adsorption capacity of Cd and atrazine increased by 9.0% and 139.4%, respectively. Compared with a single pollutant, the adsorption capacity of PB and BB for Cd increased by 4.6% and 9.3%, respectively, and the adsorption capacity of atrazine increased by 97.1% and 11.5%, respectively. The increase of atrazine adsorption after modification was higher than that of Cd. In the desorption test, ball-milled modification decreased the desorption rate of Cd and atrazine, while the desorption rate of atrazine was much lower than that of Cd. Therefore, the biochar modified by ball-milled had stronger adsorption and fixation capacity for Cd and atrazine, which provides a basis for more effective remediation of soil polluted by Cd and atrazine.