Adsorption of Lead (II) and Copper (II) ions Onalginate and Kaolinite Activated Charcoal Composite Beads

Abstract

Heavy metals pollution has become one of the most serious environmental problems today. Biobased adsorbent have attracted the attention of many researchers due to their availability, recyclability, simple modification and cost effectiveness. In this study, alginate composite beads were prepared using kaolinite clay and activated charcoal by simple dripping methods. The prepared beads were tested for the removal of Pb²⁺ and Cu²⁺ ions from aqueous solutions. The adsorption parameters such as initial pH, contact time, initial metal ion concentration and amount of the adsorbent were investigated. The experimental result showed that the adsorption of copper and lead ions followed the pseudo-second order kinetic model when compared to firstorder model. Langmuir isotherm model fitted better than Freundlich model based on the correlation coefficient greater than 0.99for both Pb²⁺ and Cu²⁺with maximum monolayer adsorption capacity of 73 mg/g and 35mg/g respectively. The results indicate that the composite beads adsorbed Pb²⁺ ions more effectively when compared with Cu²⁺ ions and therefore could be employed as a low-cost alternative adsorbent for Pb²⁺ in waste water treatment.

Keywords: Activated charcoal; alginate; kaolinite; composite; Isotherm; Kinetics