Prediction of a mathematical model to validate maximum regeneration efficiency of phenol exhausted activated carbons used in water treatment operations by domestic microwave oven

This paper describes laboratory-scale experiments examining the impact of microwave irradiation (MW) on the regeneration of spent granular activated carbons (GAC) saturated with phenol. The process was conducted in an aqueous solution using domestic microwave oven. The investigation was achieved to evaluate its adsorption efficiency after successive regeneration cycles and to ensure its practical feasibility. Different factors have been studied such as microwave power level, pH of the solution, weight of the active carbons; volume of the regenerated solution, number of adsorption and regeneration cycles. A mathematical model has been developed to measure the regeneration efficiency of the GAC adsorption capacity. It was found that, for the same power level, as the time of exposure increases, the regeneration efficiency increases. As, the microwave oven power increase from 160 to 800 W, the regeneration efficiency increases from 60 to 90% after 1.5 min of radiation time, during the regeneration process the pH of the solution increase from about 6.03 to 7.15. We concluded that (GAC) could be reused after repeated regeneration cycles under microwave irradiation while maintaining its original adsorption capacity and physical properties. It is expected that this approach could be used in ventilation systems for the treatment of volatiles organic compounds (VOCs) in work environments.