Thermodynamic and Kinetic Studies for Adsorption of Reactive Blue (RB-19) Dye Using Calix[4]arene-Based Adsorbent

A current study demonstrates the removal of Reactive Blue 19 (RB-19) from industrial wastewater by synthesizing p-piperdinocalix[4]arene-immobilized silica resin (PASR). The surface morphology and functional group analysis were performed with scanning electron microscopy and Fourier transform infrared spectroscopy. The dye removal efficiency of PASR was analyzed through adsorption studies. Different parameters were optimized such as the pH value of dye, amount of resin, concentration of dye, and effect of electrolyte on adsorption. The adsorption mechanism was analyzed with Langmuir, Freundlich, and Dubinin-Radushkevich (D-R) isotherms. It was found that experimental data follow the Freundlich isotherm, which suggests multilayer adsorption. The column adsorption study was also evaluated by breakthrough and Thomas models. The Thomas model rate constant k(TH) (cm(3) mg(-1) min(-1)) and maximum solid phase concentration was found to be q(o) = 2.702 mg.g(-1). The thermodynamic study reveals that the adsorption process is exothermic and spontaneous in nature. The kinetic study suggests that the adsorption process follows the pseudo-second-order kinetic model.