Abstract

The use of coconut husk as a low-cost natural adsorbent for the removal of Cu (II), Fe (III) and Pb (II) from simulated industrial waste effluent was studied. Batch experiments were conducted to determine the effects of varying adsorbent loadings, pH, contact time, metal ion concentration and temperature of adsorption. The adsorption of Pb (II) was found to be maximum (94%±3.2) at pH 5, temperature of 100°C, metal ion concentration of 30 ppm and contact time of 30 min. The adsorption of Cu (II) and Fe (III) were maxima (92%±2.8 and 94%±1.4) at pH range of 5 - 7, metal ion concentration of 50 ppm, temperature of 50°C but at different times of 30 and 90 min respectively. 1 g of the adsorbent material was found to be optimal for all the metal ions; the Freundlich isotherm was found to be suitable for the adsorption of Cu(II) and Fe(III) while the Langmuir isotherm was found to be suitable for the adsorption of Pb(II). The adsorption kinetics was also studied.

Key words: Metal ions, adsorption, simulated effluent, coconut husk