Adsorption study of Zinc ion onto halloysite nanotubes using taguchi’s design of experimental methodology

Abstract

In this paper, Taguchi method was applied to determine the optimum conditions for Zn (II) removal from aqueous solution by halloysite nanotubes (HNTs). An orthogonal array experimental design (L₁₆(4⁵) which is of five control factors including pH, t (contact time), m (adsorbent mass), T (temperature) and C₀ (initial concentration of Zn (II)) having four levels was employed. Adsorption capacity (mg/g) and removal percent (%) were investigated as the quality characteristics to be optimized. In order to determine the optimum levels of the control factors precisely, range analysis and analysis of variance were performed. For removal percent, the optimum condition was found to be pH=6, T=35^°C, w=0.4 g, and C₀=50 mg/L. Under these optimum conditions, adsorption capacity and removal percent can reach to 132.16 mg/g and 99.76%, respectively.