An-Najah Staff

This study focuses on preparing and studying the properties of poly itaconic acid (P.I.A) and the mechanism and effectiveness of this polymer on adsorption of phenol from the aqueous solution. The adsorption properties of the prepared P.I.A were investigated in terms of adsorbent dosage, pH, temperature, contact time, and contaminant concentration. The adsorption capacity of P.I.A was studied using Freundlich and Langmuir models at equilibrium to determine the behavior of adsorption process, if it is chemical or physical adsorption. Three kinetics models were applied to describe the adsorption process: pseudo-first-order kinetic model, pseudo-second-order kinetic model and Intra-particle diffusion model. The surface area of the polymer was determined by iodine number and BET and showed 262.5 m2/g and 355 m2/g, respectively. Results show that the optimum percent of phenol removal reached 12.2 mg/g when adsorbent dosage was 0.1g of P.I.A with a phenol concentration of 50 mg/g. When increasing pH from 4 to 12, it was found that phenol adsorbent increases slightly. The results indicate that the temperature effect is a reversible process on the P.I.A adsorption like when the temperature increases the phenol percentage of adsorption decreases. The results of the contact time studies showed that the equilibrium time for phenol adsorption process is 130 min. The percentage removal of phenol increases when the concentration of phenol increases. The results also showed that the adsorption model followed Langmuir with B equal 0.031 which indicate that adsorption is favorable. This means that a monolayer and uniform energies adsorption. The pseudo-second-order model was the best for describing the kinetic adsorption of phenol with correlation coefficient valued (R2) is 0.9975 and K2, qe of 0.0118, 11.933 respectively. This validated that the adsorption process was chemical adsorption. Thermodynamic parameters such as standard enthalpy ∆H°, standard entropy change ∆S° and standard free energy ∆G° were calculated for P.I.A adsorbent of phenol. The negative values of both enthalpy and entropy indicated that the adsorption is exothermic process and the adsorption is more favorable at lower temperature, while the positive values of Gibbs free energy at various temperatures indicate that the adsorption process is feasible but not spontaneous.