EFFECT OF RICE STRAW BIOCHAR ON CADMIUM AND LEAD UPTAKE BY PEANUT

The biochar addition to heavy metals-contaminated soil can increase the soil adsorption capacity of heavy metals and thereby decreasing plant heavy metals uptake. In this study, graphene-modified and unmodified rice straw biochar were added to Cd- and Pb-contaminated soil to reduce the peanut heavy metals accumulation. The results showed that compared with the control, the Pb and Cd content and the enrichment factor in peanuts were significantly reduced by the addition of the two biochar. The modified biochar performed better than rice straw biochar. The accumulation of Cd and Pb in the underground part for alkaline soil was reduced by 59.8% and 64.3%, respectively, while those for neutral soil by 58.7% and 53.3%, respectively. The research recommends the graphene-modified rice straw biochar for the neutral and alkaline soil remediation with Cd- and Pb-combined pollution at a level of 0.5%.