Adsorption of lead and copper using waste foundry sand: statistical evaluation

Abstract

In this study, the adsorption characteristics of lead and copper ions on waste foundry sand were investigated. Multiple regression model with dummy variables was developed to explore and to model the effects of experimental factors which are metal type, adsorbent dosage and initial concentration on adsorption capacity. According to regression model, initial concentration has a quadratic effect on adsorption capacity. The effect of concentration reaches a maximum at 296.47 mg/L and becomes negative afterward. In addition to regression analysis, the adsorption equilibrium data were analysed by using various adsorption isotherm models. Results have shown that adsorption behaviour of two metal ions could be described reasonably well by a generalised isotherm. These results indicate that waste foundry sand could be employed as low-cost material for the removal of both metal ions.