Disinfection of total coli-forms in the effluent from municipal wastewater plant with electron beam

Electron beam has introduced to investigate the effect of radiation on the disinfection of coliforms in the effluent from the municipal wastewater treatment plant. Unchlorinated secondary effluent was irradiated at different dose of 0.2 - 1.0 kGy with 1 MeV, 40 kW electron accelerator. It is observed that nearly 100% reduction in E. coli and total coliforms were achieved with a dose of 0.8 kGy. Even with the lower dose of 0.2 kGy, the E. coli and total coliforms were successfully inactivated to the level of the new guideline for discharged effluent that has been effective from 2003 in Korea. Based on the data obtained in the experiments, industrial scale plant was designed with 0.2 kGy for the flow rate of 100,000 m3 effluent per day. The overall cost for plant construction is approximately 4.0∼4.5M$, and the operation cost is around 1M$/yr. This is quite reasonable when compared to other advanced oxidation techniques such as Ozonation, UV techniques etc. (author)