Effect of adsorption variables on the removal of Cadmium ions from wastewater using activated periwinkle shell from Okada, Edo State

This paper details the effect of adsorption variables on the removal of cadmium ions from wastewater using activated periwinkle shell. The periwinkle shells were carbonized for 1.5h for 900oC, and activated using HNO3 and calcium chloride solution. The textural characteristic of the adsorbent was determined using BET surface area analysis methods, structural characterizations of the activated carbon from the periwinkle shells were performed using FTIR, SEM, and EDX. Three different concentrations of cadmium ions solution were prepared as 10mg/l, 30mg/l, 50mg/l, 80mlg/l and 100mg/l from the stock solution. The batch mode adsorption experiment of cadmium ion onto activated periwinkle shell was carried out. The effects of time of contact, pH, initial concentration, adsorbent dose, particle sizes and temperature were investigated. The result indicates that activated periwinkle shell exhibit good sorption capacity with a large surface area of 574.50m2/g and mesoporosity of 71.42%. The sorption capacity were 67.28m2/g for Cd(II) ions. The equilibrium was attained after 70mins with the particle size of 212μm. The results indicate that the pH for maximum removal of cadmium (II) ions is 6.0.