REMEDIATION OF CADMIUM AND LEAD IN CONTAMINATED SOIL USING BIOCHAR-PALYGORSKITE COMPOSITE

Abstract

. The biochar-palygorskite composite (BC/PAL) was synthesized and applied in the remediation of soil polluted by heavy metals. The efficiency of BC/PAL on the soil physicochemical property, the bioavailability and chemical fraction of Cd and Pb in the soil, the growth of the plants and heavy metals accumulation in maize ( Zea mays L.) were investigated by pot and incubation experiments. The data show that BC/PAL can greatly enhance the stability of Cd and Pb, facilitating their transition from labile to stable components. And the composite can also reduce the CaCl 2 -extractable Cd and Pb with a maximum reduction efficiency of 57.76% and 42.81%, respectively. The fresh weight of corn seedlings had a more than sevenfold increase and the accumulation of Cd and Pb in shoot and root parts decreased significantly. BC/PAL can effectively improve the contents of soil available nutrients, soil enzyme activity, and organic carbon content. It can significantly reduce the bioavailability and ecotoxicity of Cd and Pb in the soil. The biochar-palygorskite composites can be further investigated as an efficient