Optimization of Parameters Affecting Adsorption of Nickel (II), Zinc (II) and Lead (II) on Dowex 50 W Resin Using a Response Surface Methodology Approach

摘要

The effects of resin dosage, pH of the medium and contact time on the adsorption of Ni²⁺, Zn²⁺ and Pb²⁺ from battery industry wastewater using Dowex 50 W ion exchange resin were investigated. Batch-mode experiments were carried out to determine the adsorption equilibrium. The adsorption parameters were optimized using a Response Surface Methodological (RSM) approach. The Central Composite Rotatable Design (CCRD) in RSM was used to design the experiments and estimate the percentage of metal adsorption. The optimum parameters for achieving the maximum adsorption of Ni²⁺, Zn²⁺ and Pb²⁺ were as follows: resin dosage, 0.3-0.42 g; pH, 6-8.5; contact time, 90 min. Experimental results showed that the adsorption efficiency of the heavy metals was in the range of 80-100%. The results of this work suggest that RSM is a useful tool for optimizing reaction parameters and predicting response (adsorption capacity) during the ion exchange of heavy metals to achieve the desired adsorption efficiency, while reducing the number of experiments and the overall cost of treatment.