Process Control for Monitoring Disinfection of Municipal Wastewater Effluent with Ozone

摘要

Municipalities in North America are typically required to achieve some level of disinfection ofmunicipal wastewater effluent (MWWE) before discharging it to receiving water bodies. Alimited number of wastewater treatment plants have been using ozone for disinfection since1970s. This number may increase due to the efficacy of this process in oxidation of contaminantsof emerging concern besides disinfection. Transferred ozone dose, residual ozone concentrationin vent gas and in effluent are surrogate parameters currently used for the control of ozonationprocess but have their limitations. Disinfection of secondary treated municipal wastewatereffluent using ozone was studied at pilot-scale to investigate the correlation between disinfectionefficiency and surrogate parameters that are easy to monitor online. The result indicates strongcorrelation of E. coli and total coliform inactivation with reduction in UV absorption at 254 nmas well as color measured at 456 nm (R~2 value of 0.71 to 0.86).