Heavy metal phytoremediation potential of Vigna radiata (L.) Wilczek for use in contaminated regions of West Karun River, Iran

Plant-based strategies could provide a key gateway to restoring heavy metal-polluted environments. The present study was aimed to investigate the phytoremediation potential of Vigna radiata (L.) Wilczek in the heavy metal contaminated regions by oil industries at West Karun River, Iran. After soil sampling, the plants were grown in pots outdoors and irrigated by distilled water (0 mg/L Cd), Karun River water (0.04 mg/L Cd), and also by 25, 50, 75, and 100 mg/L of cadmium chloride solutions. Plants were harvested at the seedling and ripening stages and their Cadmium (Cd) content was determined. According to the results, the efficiency of V. radiata for bio-accumulation of Cd was very high at low concentrations of Cd in Karun River treatments (57% and 21% for shoot and roots, respectively), the highest Transfer Coefficient (TC) was (2.80 +/- 0.5), Translocation Factor (TF) (2.78 +/- 0.7), and Bioaccumulation Factor (BF) (3.83 +/- 0.4). Although our findings shows that V. radiata does not possess a high potential of Cd phytoremediation at high concentrations (2.47% and 4.21% in shoot and roots at 50-100 mg/L Cd, respectively), it can provide a safe alternative based at minimum level of Cd concentration. Comparison of heavy metal contents in mung bean plants and soil, shows that there is an antagonistic relationship in Cd uptake and other accessible heavy metals such as Iron (Fe), Zinc (Zn), and Copper (Cu) from the soil at the study area. Thus the V. radiata could be considered as a potent candidate for bioremediation and growing food in Cd-polluted environments.