The discharge of heavy metals (HMS) from industrial production has severely damaged the natural environment and human health. To address the challenges posed by heavy metals, a novel almond shell biochar (FeSCTS@nBC) modified with FeS and chitosan (CTS) was prepared. Scanning electron microscopy and X-ray photoelectron spectroscopy observations revealed a uniform distribution of FeS particles on the biochar. Adsorption thermodynamics experiments showed that the maximum adsorbed amounts of cadmium (Cd), lead (Pb), and chromium (Cr (VI) and Cr (III)) in FeS-CTS@nBC were 85.6, 89.63, 94.2, and 75.62 mg/g, respectively. Results of soil incubation experiments indicated that FeS-CTS@nBC had a desirable immobilization effect on heavy metals, decreasing the bioavailability of Cd, Pb, Cr (VI), and Cr (III) by 29.43%, 23.93%, 5.75% and 5.23 %, respectively. Density functional theory (DFT) calculations, revealed that the oxygen-containing functional groups on the biochar exhibited stronger adsorption capacities for heavy metals. Plant potting experiments indicated that the paddy grew well in the soil remediated with FeS-CTS@nBC. The Cd content in the roots and leaves of the paddy after nBCS2 repair was reduced by 28.01 % and 55.73 %, respectively. Overall, this work provides a promising low-cost method with a simple production process for mitigation of heavy metals from water and soil.

来源平台：SEPARATION AND PURIFICATION TECHNOLOGY