Removal of Hg 2+ , Pb 2+ , Zn 2+ and Cu 2+ ions from Contaminated Water Using Caladium bicolor (Wild Cocoyam)
Heavy metal persistence in the environment is a global threat and researchers continue to explore low-cost effective technologies for removing these contaminants from the environment. In this study, the ability of Caladium bicolor (biosorbent) to remove lead, zinc, copper and mercury ions from the contaminated water was explored. At 2 ppm metal ion concentration, the biosorbent was able to remove all four metal ions with a low removal efficiency of 79.5% for Hg 2+ and a high of 99.5% for Pb 2+ The effectiveness of the biosorbent, however, decreased when the metal ion concentration was increased beyond 2 ppm. Specifically, the biosorbent’s effectiveness was studied at 5, 10, 25, and 50 ppm metal ion concentrations. Interestingly, the decrease in effectiveness with regards to Pb 2+ was relatively marginal, suggesting a stronger preference of Caladium bicolor for lead. In order to determine optimal conditions required for effective adsorption or high metal removal efficiencies, the effect of biosorbent mass and contact time for equilibration of the biosorbent with the metals were also investigated. While 30 min contact time was found to be adequate for effective metal removal, there was no significant difference in the results obtained when 0.5 g vs 2.0 g of the biosorbent was used. FT-IR analyses also revealed that similar functional groups were responsible for the removal of all the four metals studied.
Benjamin Darko Asamoah, Ghana, Power, University of Energy & Natural Resources, ACE: Energy and Environmental Sustainability, Caladium bicolor, biofiltration, lead, copper, zinc