THERMODYNAMICS AND KINETICS ADSORPTION OF PHENOL RED ON CARBON-CuO NANOCOMPOSITE

The Carbon-CuO nanocomposite was synthesized and characterized using UV-Visible spectroscopy, scanning electron microscopy (SEM) and Fourier transformed Infrared Spectroscopy (FTIR). The nanocomposite was used as nanoadsorbent for adsorption of phenol red at the wavelength of 270 nm using UV-Visible spectrophotometer (model 6705). The effect of various parameters such as adsorbent dose, contact time, initial concentration, temperature and pH were evaluated. Carbon-CuO nanocomposite as nanoadsorbent removed 99.98% of phenol red at optimum conditions of adsorbent dose; 0.2, contact time; 40 min, initial concentration; 40 mg/L, temperature; 343K (70°C) and pH; 7. The experimental data was best fitted by the pseudo second order kinetic with R2 =0.979 than the pseudo first order with R2 =0.166. The free energy values for adsorption of phenol red on Carbon-CuO nanocomposite at various temperatures; 303, 313, 323,333, and 343 were found to be -16998.08, -17988.224, -18978.484, -19968.744, and -20959.004 J/mole respectively. The negative values of the free energy indicate that the adsorption of phenol on nanocomposite is spontaneous. The enthalpy and entropy change values obtained were 13006.914 J/mole and 99.026 J/Kmole respectively. The adsorption process was endothermic since the enthalpy value is positive. The adsorption was found to have increase in randomness at Carbon-CuO nanocomposite-phenol interface since the value of entropy change obtained is positive.