Performance evaluation of zirconium silicate composite for removal of cadmium and zinc ions

Abstract

The purification of wastewater is preferred using the adsorption technique by the column due to the high efficiency of the process. The column studies are achieved to predict the removal of pollutants and clarify the adsorption capability of these pollutants in the treatment process of wastewater. Zinc and cadmium ions are presented in both radioactive and industrial wastes. Consequently, this work focused on the removal of zinc and cadmium ions from polluted wastewater using a fixed-bed column. Zirconia–silicate composite (ZrO2–SiO2) was produced using the sol-gel technique and analyzed for this purpose. Various parameters as bed depth (2, 3, and 5 cm), flow rate (2 and 3 mL/min), and initial ions concentrations (50–200 mg/L) were investigated. The column performance was computed to be 80.3 and 79.3% for Zn2+ and Cd2+, respectively, at the optimum conditions (3 cm bed depth, 2 mL/min flow rate, and 100 mg/L ions concentration). Thomas, Adams–Bohart, and Yoon–Nelson models were performed to estimate the breakthrough curves and compute the column model parameters which are valuable for process design. Thomas model presented the highest R2 values (0.84–0.97) and offered the most accurate estimation of the adsorption process.