Dynamic Sorption of Pb2+and Zn2+ Ions with Palm (Elaesisguineensis) Kernel Husk J. A. Omgbu School of Sciences, College of Education, P.M.B. 1251, Warri. Nigeria V. I. lweanya Department of Physical Sciences, Bensu Abraka Campus, Nigeria The ion-exchange removal technique has found wide application in industrial and mining waste waters in the removal of toxic heavy metal ions, because the resins contain active ions that exchange reversibly with the metal ions in the solution without any appreciable physical change occurring in the material; it nevertheless requires the use of synthetic resins that are expensive. The need for effective and economical removal of toxic heavy metal ions (PhZf and Zn2+ ions) from mining waste waters has resulted in the search for unconventional methods and materials that might be u~eful.',~.3 Many agricultural byproducts for binding heavy metal ions bv ahsomtion andchelation have been reported by several researcheis. Kumar and Dara' reported that 63% of K+ ion and 99.87% of Hg+ ion removal could be achieved by polymerized red onion skins treated with 39% formaldehyde and 0.2 N solution of H2SOa for 2 h. Okeimen, Osuide, and Oriakhi3reported that 0.8 mglg, 2.4 mglg of Cd2+ion and 0.8 mglg, 5.7 mglg of Pb2+ion removal could he achieved from 100 mL and 800 mL of metallic solutions containing 5 mg and 40 mg of metal ions, respectively, by maize cobs. Ogbeifun, Okeimen, Nwala, and Kumsah2also reported that 2.8 mglg, 6.3 mglg of Pb2+ ion; 4.0 mglg, 2.0 mglg of Cu2+ ion, and 3.8 mglg, 1.8 mglg of Cd2+removal could be achieved from 200 m g n and 500 m g n of metallic solutions with 5 g of modified ground nut husk. Although the ion exchange methd so far is very successful in removing toxic heavy metal ions from mining waste waters using synthetic resins that are very expensve, the aim of this studv is to continue the search for less ex~ensiveand readily available agricultural byproducts such as Elaesis kernel husk that could be a.~.d i e in d the future to euineensis . industrial and mining waste waters. Methods and Materials Palm (Elaesis guineensis) kernel husk was obtained from an oil milling station near the Bendel State University Abraka Campus.
800
Journal of Chemical Education
They were deoiled by the Soxhlet extraction method using diethyl ether (32-34 'C bp) and powdered. The meal obtained was air dried and sieved throueh 500 vm mesh screen.The ~ortionthat fell helow the mrrh was fuXhrr air dried, and 50 g of i r was added tuJ6u mL of I? V V HL'I solution fur 6 h (unm Zn2+for metal ion solution. They are also comparable to those reported by Okeimen et al.%nd Ogbeifun et aL2for 5 mg metal ion solutions, although the level of metal ions removed by Elaesis guineensis kernel husk are higher than the levels reported for maize cobs but are of similar patterns, both substrates being cellulosic materials. Oil palm (Elaesis gudneensis) kernel husk could be used in the removal of toxic heavy metal ions such as Pb2+and Zn2+ from industrial and mining waste waters as shown from the dynamic sorption experiment results in Tables 1and 2. The hiph nercentwes of metal ions removed were achieved from low concentr&ions of the metal ion solutions, and, since mining waste waters are of very low concentration, quantitative removal of metal ions could be achieved with Elaesis guineensis kernel husk.
Volume 67
Number 9
September 1990
801
