Comparison of the ozonation and Fenton process performances for the treatment of antibiotic containing manure

An integrated treatment method based on magnesium salt extraction followed by chemical oxidation was used for the treatment of a veterinary antibiotic, oxytetracycline (OTC) contaminated cow manure since animal manure can be an important source for antibiotic pollution in the environment. Pretreatment with magnesium salt enhanced the efficiencies of subsequent oxidation processes by extracting 63.9% of OTC from the manure thereby making it more favorable for oxidation with the hydroxyl radicals produced by the Fenton and ozone oxidation processes. Both the 24 h Fenton oxidation process with 434 mM H2O2 and 43.4 mM Fe2+ doses and the 1-h ozonation process with an applied ozone dose of 2.5 mg min− 1 provided more than 90% OTC removal from the manure slurry. However, the second-order OTC removal rate constant of Fenton process (119 M− 1s− 1) was remarkably lower than that obtained with the ozonation process (548 M− 1s− 1). The oxidant dose was a significant factor for the efficiency of the Fenton treatment but not for the ozone treatment. The efficiencies of both the Fenton and ozone oxidation processes were not affected by the pH adjustment of the manure slurry.