Adsorptive Removal of Cadmium from Aqueous solution using Clay Obtained from Okitipupa

Abstract

Heavy metals in the air, water, soil and plants are becoming a serious health and environmental concern. Metals such as cadmium in water and food can accumulate in humans, disrupting the metabolic functions and vital organs. This study was conducted to remove Cadmium ion from water using clay soil obtained from Okitipupa. The effects of mass of clay soil, temperature, pH, contact time and initial concentration of Cd ions on the removal efficiency of the Cd from wastewater were investigated. The overall metal concentrations of the clay was determined before adsorption using Proton Induced X-ray Emission (PIXE). This was done to ascertain the suitability of the soil for Cd adsorption. However, the concentration of Cd after each adsorption studies are determined using Atomic Absorption Spectrophotometer (AAS). The results showed that 99 % (19.8 mg) of Cd2+ were removed within 20 minutes, at pH 8, 1g dosage of clay, Temperature of 25oC at 120 revolutions per minute. The value of R2 obtained for Langmuir and Freundlich isotherms are 1 and 0.8259 respectively, which indicates that Langmuir is the preferred isotherms for Cd adsorption. Similarly, results of kinetic studies showed qe = 220.95 and qe = 3.623 for pseudo first order kinetics and pseudo second order kinetics respectively. This study showed that clay soil available in Okitipupa is suitable for the removal of Cd in water. Keywords: Adsorption, Cadmium, Clay, First – Order, Water.