Abstract
Heavy metal pollution is a major global environmental issue that adversely affects the health of plants, animals, and microorganisms. Phytoremediation has emerged as an eco-friendly and cost-effective technique for removing heavy metals from contaminated soils using plants. The present study was conducted to evaluate the phytoremediation potential of Tagetes patula for lead (Pb) and chromium (Cr). Soil samples were artificially contaminated with 100, 300, and 500 ppm of each metal, and plant growth and metal uptake were assessed after harvesting. The results demonstrated that all growth parameters, including seed germination, plant height, and fresh and dry biomass, were significantly reduced at increasing concentrations of both Pb and Cr, indicating metal-induced phytotoxicity. Soil analysis after harvest revealed that residual Cr concentrations were higher than those of Pb. Metal accumulation analysis showed contrasting patterns: Pb concentrations in plant tissues decreased as soil Pb levels increased, whereas Cr accumulation in plant tissues increased proportionally with higher soil Cr concentrations. The bioconcentration factor (BCF) and biological accumulation coefficient (BAC) values for Pb were less than one, suggesting limited phytoextraction potential for this metal. In contrast, BCF and BAC values for Cr were greater than one, indicating efficient uptake and accumulation. The translocation factor (TF) for Pb exceeded one, while that for Cr was below one, suggesting greater internal mobility of Pb compared to Cr. The findings indicate that T. patula is more suitable for chromium phytoremediation than for lead extraction from contaminated soils.