Removal of metallic elements from industrial waste water through biomass and clay

Abstract

This study reports the removal of nickel(II) and copper(II) ions (Ni2+ and Cu2+) from aqueous solution using pure and chemically pretreated biomass from Arachis hypogea (peanut shells), Prunus amygdalus (almond shells), Arundo donax (giant cane) and two clay materials, clay G and clay B. These materials are indigenous, easily available, surpulus by-products for biosorption studies. Batch experiments were carried out to determine the effect of various adsorbent factors such as initial pH, temperature, particle size and contact time on the adsorption process. For adsorption application, up to 99% removal of both metal ions was achieved by biomass and clay materials. Furthermore, chemically modified adsorbents significantly increased the uptake capacity of biomass, suggesting that the affinity between metal and sorbent can be increased after pretreatment. Equilibrium isotherms were analyzed using Langmuir and Freundlich isotherm models, and both models fitted to explain the adsorption behavior of metal ions on to biomass and clay. This shows that the adsorption of metal ions on the adsorbent is a physical adsorption mechanism. In conclusion, owing to its outstanding nickel(II) and copper(II) uptake capacity, the utilized biomass proved to be an excellent biosorbent.