Remediation potential of <i>Albizia lebbeck</i> L. Benth. in chromium contaminated soil

Abstract

Heavy metals contamination has been of great concern in the last decades because of their health hazards to man and other organisms when accumulated within a biological system. This study investigated Albizia lebbeck species for removal of chromium (Cr) from contaminated soil. Pots experiment consisting of five treatments (Control: 0mg Cr/kg), (50 mg Cr/kg), (100mg Cr/ kg), (150mg Cr /kg), (200mg Cr/kg) and replicated five times in a completely randomized design were used in this study. The study was carried out for a period of 12 weeks after transplanting. Growth parameters such as seedling heights stem diameter and number of leaves were assessed at the end of the experiment. Bioaccumulation factor (BAF) and translocation factor (TF) were used to assess the phytoremediation potentials of the seedlings. Physicochemical properties of the soils; Cr concentrations in soils before and after experiment and those of the plants were determined using standard instrumentation techniques. The respective mean seedling heights, stem diameter and leaf production throughout the weeks of the experiment from the treatments were: 0mg Cr/kg (6.11-14.32cm; 0.20 - 0.30mm; 1.50 - 3.21), 50mg Cr/kg (10.56-18.67cm; 0.20 - 0.28mm; 1.60 – 3.22), 100mg Cr/kg(10.99-12.03cm; 0.21 – 0.27mm; 1.61 – 2.21), 150mg Cr /kg(11.87-15.12cm; 0.22 – 0.26mm; 1.41 – 2.32) and 200mg Cr/kg(12.02-15.78cm; 0.21 – 0.26mm; 1.10 – 2.43). There were no significant differences among the treatments for the growth parameters of the Albizia lebbeck seedlings at p≤0.05. Values of BAF (0.00-0.11) and TF (0.00-0.61) of Cr in the plants indicate low potential of this plant for phytoextraction of chromium. This study has shown that Albizia lebbeck are low- efficient plant for remediation of soil contaminated with chromium.