Performance and modeling of continuous ion exchange processes for phenols recovery from olive mill wastewater

Abstract

A continuous-flow ion exchange (IE) process for phenols recovery from olive mill wastewaters was examined through both strong-base and weak-base anion exchange resins. The effect of initial pH showed that phenols removal efficiency increased with an increase in the pH value up 7 and efficiency remains constant at higher pH values for Amberlyst A26. On the other hand, phenols removal efficiency for Amberlite IRA-67 also increased with an increase in the pH value up 7, reaching phenols removal efficiencies close to 57%. In addition, Thomas, Yoon–Nelson and Clark models were applied to the experimental data to predict the breakthrough curves. The simulation of the best-performing operational condition was used to evaluate the process performances for different inlet phenols concentrations (5, 25 and 100mgL−1). The results showed an increase in initial phenols concentration improved the adsorption capacity. In both cases, the Thomas model was found to give best fit to experiment data for the three initial phenols concentrations, followed by the Yoon–Nelson and Clark models. Finally, column regeneration studies showed almost 100% phenols recovery efficiencies were obtained. IE process led to a phenols solution susceptible to be concentrated and used in food, cosmetic or pharmaceutical sectors.