Experimental and modeling studies of the removal of phenolic compounds from olive mill wastewater by adsorption on sugarcane bagasse

Abstract

Olive mill wastewater (OMW) poses severe problems for aquatic and environmental systems, especially in the Mediterranean region, therefore, its treatment is of great interest. This study aimed the removal of phenolic compounds from OMW by sugarcane bagasse (SCB) as a low-cost adsorbent. Different parameters influencing the adsorption such as adsorbent dose, solution of pH, contact time and temperature were optimized. I was found that SCB can be used as an effective and low-cost adsorbent to remove phenolic compounds from OMW. Application of experimental design approach showed an optimum of 60% removal after 60 min at 60 °C and pH of 12. Langmuir and Freundlich isotherm models were used to describe the equilibrium date, while kinetics data were fitted to pseudo-first-order and pseudo-second-order kinetic models. The obtained results showed that the equilibrium data were best fitted to Freundlich model. The Langmuir model also gives good correlation and shows an adsorption capacity of 57.7 mg/g. kinetics data followed pseudo-second-order model instead of pseudo-second-order model. The thermodynamic parameters including ∆G°, ∆H° and ∆S° were also investigated and suggested an exothermic process. In addition, high energy value of SCB both before (13.15 MJ/kg) and after adsorption (15.58 MJ/kg) indicates its potential for use as an alternative energy source.