Tests exploration et evaluation de la sorption du phenol par les noyaux de datte .

Abstract

In this work, the adsorption of phenol on activated carbon derived from date stones was studied. The adsorbent was characterized by infrared spectroscopy (IR) analysis, the value of pH zero charge point was experimentally set to 7.48. Analysis of surface functions by the Boehm method showed that the surface of the adsorbent has neutral functions. The methylene blue, iodic and phenolic indexes of the adsorbent were also evaluated. The adsorption performance of date stones was evaluated by varying experimental conditions such as pH, contact time, initial adsorbent dosage, phenol initial concentration and temperature. The maximum adsorption yield was 90.165% with the initial concentrations ranging from 10 to 50 mg/L. The results showed that the increase in adsorbent dosage from 2.5 to 20 g/L significantly increased the phenolic compounds adsorption rates from 27.573to 82.387 %. Removal of pollutant was observed to be most effective at lower pH. Kinetics study showed that the adsorption agreed well with pseudo-second-order model. Demonstrating the formation of mono-molecular layer on the surface of the adsorbent during adsorption process Freundlich,Langmuir and Temkin isotherm models were applied to the equilibrium data. The results showed that Langmuir equation fits better than the Freundlich and Temkin equations. The activated carbons response "yield" was analyzed as a function of the experimental parameters (contact time, pH, adsorbent dosage, pollutant initial concentration and temperature), using the complete factorial design of 32 experiments. The response has been described by a first order model that was adequate to predict responses in all experimental regions. The experimental values obtained were in good agreement with the values predicted from the model, with relatively small errors between the predicted and the actual values. Through this study, we have confirmed that the activated carbon derived from date stones has a large capacity for adsorption, making it an effective and inexpensive adsorbent in the removal of phenolic compounds in aqueous solutions