BIOREMEDIATION OF METALLIC IONS FROM AQUEOUS SOLUTION

Use of Moringa oleifera seed pods (MSP) and Arachis hypogea nut shells (ANS) as a bio-remedial approach for removal of selected metals (copper, zinc, lead, cadmium, and iron) from synthetic contaminated water was investigated. Batch experiments were used for the bio-sorption of the metal ions. Removal parameters such as contact time, particle size, sorbent dose, and initial metal concentration were optimized. Determination of residual metal ions after employing sorbent was done using flame atomic absorption spectroscopy (FAAS). The removal efficiency of the two materials is compared. Using 20 ppm synthetic metal ion mixture in 50mL of water sample, the optimized parameters for Moringa seed pods were 150 min contact time for Cd and Cu while 100 minutes for Pb and Fe, 2.0 g of sorbent dose (except Fe which had its highest removal using 0.5 g sorbent). While using Arachis nutshells, the optimized conditions were 150 min for Pb, Cd and Fe, while 100 minutes for Cu and 2.0 g of sorbent dose. The decrease in removal with increasing particle size was observed for both ANS and MSP. Similar result was observed for both the sorbents as the initial metal concentration was increased, the removal efficiency was increased and after saturation, percentage removal is constant. Removal of Pb by both the sorbents was highest followed by Cd, Cu, Zn and Fe. These non-edible plant parts for Arachis and Moringa plants are proposed as a cheap, simple, and an effective alternative for purification of water contaminated with heavy metals.