Affiliation:
1. Department of Chemistry, College of Natural and Computational Science, Wollega University, Nekemte, Ethiopia
Abstract
Powdered Activated Carbon Adsorbent produced from Anchote peel (Coccinia abyssinica peel). Powdered Activated Carbon Adsorbent was investigated for its adsorption capacity for Cadmium (II) ion. Effects of parameters: pH, contact time, adsorbent dose, initial metal ion concentration, and temperature on adsorption of Cadmium (II) ion were investigated. The best adsorption of Cadmium (II) ion occurred at pH 5, where the adsorption reached equilibrium within 210 min. for the optimum 0.025 mg/l initial Cadmium (II) ion concentration. Kinetic studies of the data showed that the adsorption follows the pseudo second order kinetic model where equilibrium adsorption capacities and adsorption rate increased at optimum level for all parameter. Fourier Transform Infra Red spectra of activated carbon adsorbent & Cadmium (II) ion loaded adsorbent were obtained. The enthalpy of Cadmium (II) ion adsorption was -71.986 J/mol. The negative enthalpy of adsorption indicated an exothermic nature of the adsorption. The equilibrium data better fitted Freundlich isotherm models within the temperature range 20 °C – 45 °C. Maximum adsorption efficiency of adsorbent was 98.3% of Cadmium (II) ion at pH 5 and optimum contact time 210 min., adsorbent dose 0.25 g and initial conc. 0.025 mg/l respectively. The maximum adsorption capacity of Anchote (Coccinia abyssinica) peel activated carbon adsorbent was observed to 89.273 mg/g of Cadmium (II) ion at 30 °C and 5 mg/l.