Residue in the Mangrove Surface Sediment with the Feasibility of Phytoremediation Application

Abstract

The present study investigated heavy metal contaminations in the mangrove surface sediment of Rayong coast, Thailand. Sediment samples were collected from 5 locations with each 3 sampling sites and analyzed for heavy metal (Cu, Pb, Cr, Zn and Mn) contents using microwave digestion and MP-AES. The results revealed that concentrations of the heavy metals ranged from 10.54-66.53 mg/kg for Cu, 21.71-116.40 mg/kg for Pb, 21.21-66.66 mg/kg for Cr, 17.67-397.01 mg/kg for Zn and 46.55-1609.53 mg/kg for Mn. Although, the concentrations of Cu, Pb and Zn in surface sediments exceed the effects range low (ERL), did not exceed the effects range median (ERM) of the guidelines. Meanwhile, the feasibility of treating a heavy metal-contaminated soil via mangrove phytoremediation showed the removal efficiency of heavy metals contaminated in sediment occurred in descending order of Mn>Pb>Cr>Cu>Zn (93.11, 80.42, 70.03, 67.09 and 52.50 %, respectively). After spiked more concentration of heavy metals, decreasing removal efficiency was occurred in all treatments that might be caused of the higher heavy metal intake. Beside of these contaminated conditions, the mangrove plants can still survived after 30 days. Which indicated the tolerated to the high level of heavy metals.