The Role of Bacterial Biosorption in Mitigating Hexavalent Chromium Toxicity in Contaminated Soil

Hexavalent chromium (Cr(VI)) is a highly toxic and carcinogenic heavy metal that poses a significant threat to soil ecosystems and human health. Traditional methods for the remediation of Cr(VI)-contaminated soils, such as chemical reduction and physical extraction, are often expensive and environmentally disruptive. This study investigates the potential of bacterial biosorption as a cost-effective and eco-friendly alternative for mitigating Cr(VI) toxicity in contaminated soils. Several bacterial strains, including Bacillus, Pseudomonas, and Escherichia coli, known for their metal-binding capabilities, were isolated from Cr-contaminated sites and evaluated for their biosorption efficiency under varying environmental conditions. The mechanisms of Cr(VI) reduction and adsorption by bacterial biomass were explored through spectroscopic and microscopic techniques. Key factors influencing biosorption, such as pH, temperature, bacterial cell surface properties, and Cr(VI) concentration, were optimized to enhance removal efficiency. Results indicated that bacterial biosorption not only effectively reduced Cr(VI) to the less toxic trivalent form (Cr(III)) but also immobilized it, preventing further leaching into groundwater. The study highlights the potential application of bacterial biosorption in large-scale bioremediation strategies for Cr(VI)-contaminated soils, contributing to sustainable and environmentally friendly pollution control methods. Further research into genetic and metabolic engineering of bacterial strains may enhance biosorption efficiency and broaden the scope of its application.