Removal of heavy metal ions in aqueous solutions using palm fruit fibre as adsorbent

Abstract

The ability of the biomass of palm fruit fiber in removing Pb, Cu, Ni and Cr from aqueous solution was investigated as a function of concentration, contact time and pH variations. Palm fruit fiber from the study locations were washed with deionized water, air-dried and ground using electric grinder. The powdered fiber was sieved and treated with 0.3 M HNO3 solution for 24 h, washed with deionized water until pH 7.2 and oven dried at 60°C. The biomass was added to 1 M stock metal ion solutions made from Copper sulphate, Potassium dichromate, Lead nitrate and Nickel sulphate. The concentrations, contact time and pH of each stock solution were varied. The mixtures were shaken, filtered and analyzed by GBC Avanta Atomic Absorption Spectrophotometer version 2.02. The results showed mean percentage recovery of 51.08% Pb, 54.75% Cu, 46.96% Ni and 44.91% Cr for concentrations, 96.96% Pb, 9.79% Cu, 49.21% Ni, and 7.63% Cr for contact time and 87.48% Pb, 82.86% Cu, 56.71% Ni and 37.68% Cr for pH. The application of the biomass to waste water showed percentage removal of 73% Pb, 78% Cr, 82% Cu and 87% Ni. The mean percentage removal value revealed Pb as the highest and Cr as the least adsorbed. The sorption capacity of the biomass decreased with increasing concentration of metal ion but increased with decreasing pH and increasing contact time. Chemical modification of the biomass enhanced its capacity. Thus the palm fruit fiber biomass is cost effective and has great potential for use as adsorbent in removing heavy metals from aqueous solutions.   Key words: Palm fruit fiber, heavy metal, biomass, ion, adsorbent, contact time, percent removal.