AOPs(Advanced oxidation process) for the treatment of water and wastewater are being condidered as a practical alternative for the disinfection of bacteria and viruses due to their high effictiveness and environmental compatibility. Batch kinetic experiments were conducted to evaluate the disinfection efficiencies of a wastewater effluents for UV and gamma radiation. Monitering for 5 months was also performed for the effluents treated with UV and gamma radiation, separately. The results of the monitoring of wastewater treatment plant at J city showed that the UV disinfection efficiencies were 21-99 % and 19-85 % for the total bacteria and total coliform, respectively, while for the gamma radiation both were 99.9 %. Microbial regrowth after UV and gamma radiation disinfections were also evaluated for 4 days. Significant microbial regrowth was observed for the UV-disinfected effluent, while there was almost no microbial regrowth for the gamma radiation disinfection at 0.25 and 0.5 kGy.