Ozonation of cephalexin antibiotic using granular activated carbon in a circulating reactor

A circulating reactor was used to decompose cephalexin during catalytic ozonation. The effect of ozone supply and granular activated carbon (GAC) catalyst was investigated for removal of CEX and COD. The regeneration of exhausted activated carbon was investigated during in-situ ozonation. According to results, ozone supply appeared as the most influencing variable followed by dosage of granular activated carbon. The BET surface area, thermogravimetric analysis (TGA) and temperature programmed desorption (TPD) curves indicated that solid phase regeneration of activated carbon using ozone gas followed by mild thermal decomposition was very effective. The adsorption capacity of regenerated activated carbon was slightly lower than virgin activated carbon. The overall study revealed that catalytic ozonation was effective in removing cephalexin from solution and the method can be applied for in-situ ozonation processes.