Treatment of an industrial chemical waste-water using a granular activated carbon adsorption-microwave regeneration process

BACKGROUND: Industrial waste-water is posing an ever-greater environmental hazard. Recently, a process for purification combining activated carbon adsorption and microwave regeneration has drawn much attention. In this study, the effectiveness of this process for the treatment of industrial waste-water from a chemical plant was tested. RESULTS: The effects of various factors including solution pH, granular activated carbon (GAC) dosage and contact time on the adsorption efficiency of organic compounds were studied. The regeneration of the exhausted GAC under microwave radiation was investigated, and the optimal conditions were: microwave power 400 W, radiation time 3 min for 10 g GAC. Under the optimal conditions the regenerated GAC recovered 97.6% of its original adsorption capacity. Repetitive uses of the GAC showed that it maintained a stable performance in the first few repetitions, but a decrease was observed after further repetitions. A GAC weight loss of about 10% at the sixth repetition was observed and a decrease in the surface area and increase in the surface basicity were observed for the regenerated GAC. Economic evaluation of the microwave regeneration process suggested that the total cost was about 24.3% of the GAC price at a pilot scale. CONCLUSIONS: A satisfactory regeneration of the chemical waste-water exhausted GAC could be achieved under microwave radiation. The GAC adsorption-microwave regeneration process was applicable for the treatment of this chemical waste-water. Copyright (c) 2012 Society of Chemical Industry