Phytoremediation of Heavy Metals Nickel, Cadmium and Lead in the Coasts of the Persian Gulf Using Mangrove (Avicennia marina)

Phytoremediation is one of the most important sustainable biological methods to deal with the increasing effects of pollutants. In this study, the efficiency of Avicennia marina for refining heavy metals such as lead, cadmium and nickel from aqueous media was investigated. For sampling of mangroves and sediments in 2019, 20 stations throughout Khorkhoran wetland located in the west of Bandar Abbas were identified and samples were collected from water, sediments and different parts of the plant. According to the results, the highest accumulation of metals with a value of 4.38 mg/kg in the root of mangrove was related to lead and the lowest accumulation of metals with a value of 0.261 mg/kg in the root of the mangrove was related to cadmium. The results of transfer coefficient for lead and cadmium in mangrove roots was greater than 1 and for nickel less than 1. Moreover, there was a statistically significant correlation between pH and temperature parameters with the mean concentration of all heavy metals in sediment and between EC and the mean concentration of all heavy metals except nickel in water (P> 0.05). According to the results, the difference in the concentration of metals in the leaf and root tissue of mangroves may be due to differences in the physiological structure of the tissues; Therefore, mangrove roots seem to be more suitable than heavy leaves for refining heavy metals.