Comparison of different kinetic models for adsorption of acid blue 62 as an environmental pollutant from aqueous solution onto mesoporous Silicate SBA-15 modified by Tannic acid

In this work, adsorption kinetics were investigated in order to remove the acid blue 62 off the aqueous solutions using mesoporous silicate SBA-15 loaded with tannic acid (tannin-SBA-15). Nitrogen adsorption and desorption test (BET), X-ray diffraction (XRD) and Fourier transform infra-red spectroscopy (FT-IR) analysis characterize synthesized composite. The impacts of some parameters such as PH, adsorbent dosage as well as contact time were studied and optimized at temperatures between 25 to 45 oC. The study also was conducted on intra-particle diffusion, pseudo first-order, pseudo second-order and Elovich kinetic models. In order to have the best correlation with the experimental data, the model of the second-order kinetics was discovered. The model of the intra-particle diffusion represents that both boundary layer and intra-particle diffusion processes control the mechanisms of adsorption of acid blue 62 onto tannin-SBA-15.