Adsorption and Optimization Removal of Co(tsPc)-4 from aqueous solution using Nanoalumina

Abstract

In the present study, adsorption of Co(tsPc)-4 using γ-Alumina was investigated. γ-Alumina was prepared by gel combustion method. The XRD pattern revealed that the synthesized γ-Alumina is amorphous and SEM image showed its nanosize scale while BET surface area about 501 m2/g and pore size of 7 nm implies highly porous surface which is a characteristic property of a high-quality adsorbent. In the second step of this study, the effects of adsorbent dosage, initial Co(tspc)-4 concentration and contact time were investigated. Upon the obtained UV-Vis spectra, λmax of 664 nm was used to determine the concentration of Co(tsPc)-4 after adsorption. From the Langmuir isotherm the maximum adsorption capacity of γ-Alumina toward Co(tsPc)-4 was determined (Qm=333.33 mg/g). Although Co(tsPc)-4 adsorption occurred in the first 40 min of contact time, at least 90 min time was needed to attain equilibrium. The kinetics of adsorption can be described by second order rate equation. After that, statistically based experimental design, i.e. as Box–Behnken design (BBD), was used to study the effect of independent variables on the adsorption. Regeneration studies of the adsorbent were carried out and it was found that the adsorbent can be effectively regenerated up to 3 times with no significant deactivation. The obtained results suggest γ-Alumina is high quality adsorbent for the removal of Co(tsPc)-4 from aqueous waste streams in different industries such as painting and oil & gas in MEROX unit.