Adsorption of Reactive Blue 19 onto Activated Carbon Prepared from Pomegranate Residual by Phosphoric Acid Activation: Kinetic, Isotherm and Thermodynamic Studies

In this study, the adsorption of Reactive blue 19 onto pomegranate residualbased activated carbon was investigated in aqueous solution. The activated carbon prepared by phosphoric acid activation under air condition. PRAC was characterized for its surface chemistry by point of zero charge measurements, Scanning Electron Microscopy and nitrogen adsorption at 77 K. The effect of operational parameters including contact time, initial pH, adsorbent dose, initial dye concentration and particle size were studied. Results showed that an optimum dye removal efficiency (96.7%) was observed at initial pH=11, contact time of 5 min, adsorbent dose of 3.25 g/L, initial dye concentration of 200 mg/L, and particle size of 63-149μm. The adsorption process was found to follow the Temkin isotherm equation (R2=0.975) and second-order kinetic model (R2=0.999). Furthermore, thermodynamic parameters such as ΔG°, ΔH°, and ΔS° were calculated.