抄録
In the present study, granular gibbsite with vinyl acetate (20%, G-GB20) was used for the removal of phosphate from artificial sewage. The amount of phosphate adsorbed was studied using batch techniques. The effect of different parameters, namely contact time, initial concentration, solution pH, and temperature were investigated. The adsorption kinetics data were best described by the pseudo-second-order rate equation and equilibrium was achieved after 12 h. The Langmuir and Freundlich equations for describing adsorption equilibrium were applied to the experimental data. The correlation coefficients of the Langmuir and Freundlich equations were 0.960 - 0.996 and 0.960 - 0.995, respectively. A number of thermodynamic parameters, namely free energy, enthalpy, and entropy change for the adsorption of phosphate were evaluated and it was found that the reaction was spontaneous and endothermic in nature. Adsorbent (G-GB20) was used for repeated adsorption and desorption of phosphate and a breakthrough curve was obtained. It was shown that G-GB20 could be used three times for repetitive adsorption and desorption of phosphate. Results suggest that the prepared G-GB20 has great potential in the remediation of water contaminated by phosphate.