Effect of Salinity and PH on the Industrial Effluent Treatment by Activated Carbon: Modeling of the Kinetic Adsorption and Equilibrium Isotherms

In recent years, interest has been focused on the removal of phenols from contaminated by using a variety of purification techniques. Adsorption of bio-industrial effluent on commercial activated carbon S23 was investigated at ambient conditions. In this wok, phenol and p-hydroxyl benzoic acid (PHBA) was studied as an example of the organic compounds present in the industrial effluent. The effect of temperature, pH, and the presence of inorganic salt NaCl on the pollutants adsorption were studied to give further comprehension of the optimal conditions of the organic compounds adsorption onto activated carbon. It was noted that the increase in temperature resulted in a decrease in phenols adsorption capacity by S23. Lower phenol adsorption was also observed at the solution pH 2 and 10, whereas, favourable adsorption was reached at neutral solution pH, and the coexisting inorganic salt NaCl exerts slightly positive effect on the adsorption process. The isotherms obtained at pH 2.2 and 3.5 (non-buffered solution) are very similar and showed a higher adsorption capacity compared with that obtained at pH 7 and 10 for PHBA which is more adsorbable than phenol. The kinetic of the adsorption processes can be better represented by the pseudo-second order. The results showed also that the total organic carbon (TOC) of the industrial effluent reduced for about 20 %. Freundlich, Langmuir and Jovanovic adsorption models were used for mathematical description of adsorption equilibrium of phenols. The results showed that the experimental data fitted very well to the Freundlich and Jovanovic models.