Application of experimental design for removal of sunset yellow by copper sulfide nanoparticles loaded on activated carbon

In this study, copper sulfide nanoparticles loaded on activated carbon (CuS-NP-AC) was synthesized by novel, low cost and green approach and characterized using different techniques such as SEM, and BET. This material was used for the removal of sunset yellow (SY) from aqueous solutions was investigated. The dependency of removal percentages to variables such as pH, initial SY concentration, adsorbent dosage and sonication time were studied by central composite design (CCD) coupled with response surface methodology (RSM) by considering the desirability function (DF). The accuracy and ability of method at optimum values predicted by this model was studied by conduction of similar experiments at the same previously optimized conditions. A good agreement between experimental and predicted data was achieved that efficiency of this model for prediction of real optimum point. Among the well known previously isotherm models, the experimental equilibrium data efficiently can be represented by the Langmuir model, while the rate of adsorption. Kinetic data efficiently can be interpreted by combination of pseudo-second order as well as intraparticle diffusion models. The small amount of this adsorbent (0.016 g) is applicable for removal of high amount of SY (>90%) in reasonable time (17 min).