Investigation of Acid Blue 62 Dye Adsorption using SBA-15/Polyaniline Mesoporous Nanocomposite: Kinetic and Thermodynamic Study

Background and This study aimed to investigate the adsorption of Acid Blue 62 (AB62) as an anionic dye from aqueous solution onto as SBA-15/Polyaniline (SBA-15/PAni) mesoporous nanocomposite a low-cost adsorbent and feasible.
Fourier transform infra-red spectroscopy (FTIR), Filed Emission Scanning Electron Microscope (FESEM), Transmission Electron Microscope (TEM), X-ray Diffraction (XRD), and BET were used to examine the structural characteristics of obtained adsorbent. The effective parameters on batch adsorption process such as pH, dosage, and time were investigated and optimized. For determining the type of kinetic model, pseudo first order, pseudo second order, Elovich and intra-particle diffusion kinetic models were applied. Thermodynamic parameters such as changes in Gibbs free energy (ΔG°), enthalpy (ΔH°), and entropy (ΔS°) were calculated.
Maximum BET specific surface and pore volume on the adsorbent were 224.4 m2/g and 0.46 cm3/g, respectively. The obtained optimized condition was as follows: pH=2, time=60 min, temperature 25° C, and adsorbent dose = 0.3 g/l. The adsorption kinetic data well-fitted by pseudo-second order kinetic equation. The negative values of ΔG° and ΔH° (- 4.012 KJ/mol) and the positive value of ΔS° (0.409 J/mol K) showed that the AB62 adsorption process was spontaneous, physi-sorption, feasible and exothermic.
SBA-15/PAni can well be used as a low-cost surface adsorbent for removal of AB62 from aqueous media.