Novel magnetite nano-rods-modified biochar: a promising strategy to control lead mobility and transfer in soil-rice system

Environment-friendly and cost-effective remediation strategies are highly needed to reclaim the lead (Pb) contaminated soils. The present study evaluated the efficacy of novel magnetic wood-modified biochar (MWB) and pristine wood biochar (WB) at different application rates (0.5-1.75%) for remediation of Pb-contaminated soil. Both MWB and WB amendments effectively reduced the transfer and bioavailability of Pb in the soil. MWB (1.75%) amendment remarkably influenced rice plant growth in terms of improved biochemical and physiological attributes. The amendment of Pb-contaminated soil with MWB also proved beneficial in reducing oxidative stress in rice plants. A significant increase in root iron plaque (Fe-plaque) formation was also observed with 1.75% MWB treatment. The sequential extraction results demonstrated the increased transformation of exchangeable Pb fractions to non-exchangeable Pb fractions. Application of 1.75% MWB reduced the Pb content in roots and shoots by 48.6% and 60.2%, respectively. Present findings clearly validated the usefulness of MWB as a cost-effective remediation strategy for Pb-contaminated soil.