Comparative Evaluation of Phytoremediation Potential of Laportea Aestunans L. and Tithonia Diversifolia for Cadmium Metal Remediation

Abstract

In this study, the phytoremediation potential of Laportea aestunans L. and Tithonia diversifolia (sunflower) in a cadmium contaminated soils were investigated. Soil was collected within the Federal University of Technology Akure premises at the afforestation farm, the soil samples were air dried, picked for obvious gravel, and sieved through 2mm mesh. The physicochemical properties of the soil samples were determined using standard methods. The soil samples were spiked with different concentration of cadmium. Virgin and spiked soil samples were extracted using aqua regia and extracted solution analysed with Atomic Absorption Spectrophotometer (AAS) for cadmium metal. Seeds of both Tithonia diversifolia and Laportea aestuans were planted in untreated (control) and treated soil samples in triplicates; experiment was terminated after 8 weeks. From the experiment, the leaf of both plants accumulated more of the metal followed by the stem and the root. The bioaccumulation factor for both plant in all samples were all found to be less than one which confirms both plants to be excluders, however, Tithonia diversifolia is closer to one which indicates a better phytoremediator. This implies that Tithonia diversifoliais more suitable for phytoremediation of cadmium metalthan Laportea aestuans.