Effectiveness of sawdust-derived biochar in reducing lead contamination and enhancing soil quality parameters

Background: Biochar has emerged as a sustainable and cost-effective amendment for remediating heavy metal-contaminated soils. This study investigated the effectiveness of sawdust-derived biochar in reducing lead (Pb) contamination, improving soil pH and organic matter, and its impact on seed germination in Pb-contaminated soil. Methods: A laboratory-scale experiment using a post-test control design was conducted with soils treated with 1%, 4%, and 7% biochar concentrations. Measured parameters included Pb concentrations, pH levels, organic matter content, and germination rates of mung bean seed. Results: Biochar application reduced Pb concentration by up to 98.19% and increased soil pH from 6.2 to 7.45. Organic matter content reached 62.92% at 7% biochar. However, seed germination rates declined at higher concentrations, with the highest germination rate (81.67%) observed at 1% biochar. Differences among treatments were statistically significant (P<0.05). Conclusion: Sawdust-derived biochar effectively reduces Pb contamination and improves soil pH and organic content, offering a sustainable remediation solution. However, higher application rates may negatively affect seed germination, indicating the need for optimized dosage in future applications.