Copper(II) and lead(II) removal from aqueous solution in fixed-bed columns by manganese oxide coated zeolite

Abstract

The ability of manganese oxide coated zeolite (MOCZ) to adsorb copper and lead ions in single- (non-competitive) and binary- (competitive) component sorption systems was studied in fixed-bed column. The experiments were applied to quantify particle size, bed length, influent flow rate and influent metal concentration on breakthrough time during the removal of copper and lead ions from aqueous solutions using MOCZ column. Results of fixed-bed adsorption showed that the breakthrough time appeared to increase with increase of the bed length and decrease of influent metal concentration, but decreased with increase of the flow rate. The Thomas model was applied to adsorption of copper and lead ions at bed length, MOCZ particle size, different flow rate and different initial concentration to predict the breakthrough curves and to determine the characteristic parameters of the column useful for process design. The model was found suitable for describing the adsorption process of the dynamic behavior of the MOCZ column. The total adsorbed quantities, equilibrium uptakes and total removal percents of Cu(II) and Pb(II) related to the effluent volumes were determined by evaluating the breakthrough curves obtained at different conditions. The results suggested that MOCZ could be used as an adsorbent for an efficient removal of copper and lead ions from aqueous solution. The removal of metal ion was decreased when other additional heavy metal ion was added, but the total saturation capacity of MOCZ for copper and lead ions was not significantly decreased. This competitive adsorption also showed that adsorption of lead ions was decreased insignificantly when copper ions was added to the influent, whereas a dramatic decrease was observed on the adsorption of copper ions by the presence of lead ions. The removal of copper and lead ion by MOCZ columns followed the descending order: Pb(II) > Cu(II). The adsorbed copper and lead ions were easily desorbed from MOCZ with 0.5 mol l −1 HNO 3 solution.