Phytoremediation Potential of Millettia pinnata (Karanj) in Industrial Waste Contaminated Soils: A Review
Millettia pinnata is a fast-growing, drought-tolerant, nitrogen-fixing leguminous tree that has attracted considerable attention for its ecological, economic, and environmental significance. This review aims to evaluate the phytoremediation potential of Millettia pinnata in industrial waste-contaminated environments and to examine the physiological, biochemical, and ecological mechanisms that support its remediation efficiency. Available studies indicate that the species can effectively tolerate, accumulate, stabilise, and detoxify a wide range of contaminants, including chromium, nickel, copper, zinc, manganese, and lead. Its strong antioxidant defence system, extensive root architecture, and symbiotic association with nitrogen-fixing rhizobia enable successful growth in nutrient-deficient and polluted soils while enhancing soil fertility and ecosystem recovery. Furthermore, the species provides significant economic benefits through the production of biodiesel, sustainable aviation fuel, organic fertilisers, biopesticides, and activated carbon. These multifunctional attributes make Millettia pinnata an attractive option for integrating environmental remediation with sustainable resource utilization. Overall, the evidence highlights the considerable potential of Millettia pinnata as a sustainable tool for contaminated land management, ecological restoration, carbon sequestration, and renewable energy production. However, further long-term field-based studies are required to optimize its large-scale application and improve its effectiveness under diverse environmental conditions.