Abstract

Contamination by potential toxic elements (PTEs) is a severe problem threatening soil environment and human health worldwide. The present study investigated an electronic waste (e-waste) site in Nigeria contaminated by PTEs including Cd, Cr, Cu, Ni, Pb and Zn. Eight plant species (Pennisetum purpureum, Pentodon pentandrus, Amaranthus spinosous, Kyllinga pumila michx, Alternanthera sessilis, Cyperus dissiformis, Colocassia esculenta, Tridax procumbens) were analysed for their bioaccumulation abilities for PTEs. These plant species showed different PTE bioaccumulation capabilities, and Zn, Cu and Pb had the highest average contents in tissues of all plants. Most PTEs were accumulated in plant roots, followed by leaves and stems. Chromium and Cd were priorly accumulated in plant tissues due to their significantly higher bioaccumulation concentration factors (BCFs) than other PTEs. Among the studied plant species, P. purpureum and T. procumbens possessed a significant difference in PTE uptake pattern, suggesting different pathways in PTE accumulation and internal transportation. The bioaccumulation capacity of Ni and Cu significantly varied among the investigated plant species, whereas Zn, Pb, Cr and Cd showed similar bioaccumulation capacity. The present study contributed to a better understanding of PTE bioaccumulation by plants and suggested potential candidates for phytoremediation process at e-waste dumping sites.

Key Words: E-waste, Accumulation, Bioaccumulation concentration factor (BCF)