Disinfection of a municipal wastewater secondary effluent with a combination of ultraviolet irradiation and peracetic acid

In this study, the use of UV and peracetic acid, and their combinations, was investigated on secondary effluent from Maxson wastewater treatment plant in Memphis, TN. The effluent tested was particularly suitable for the combination of UV and PAA because of its low UVT and high initial E. coli concentrations (in the range of 105 – 106 MPN/100 mL).Inactivation kinetic models were generated for the UV and PAA disinfection processes and a novel, pseudo-mechanistic model was developed for modelling the UV+PAA process. The use of two processes could lead to substantial savings by leveraging two separate disinfection mechanisms (DNA-based for UV and cell membrane-based for PAA) such that these mechanisms could be exploited simultaneously and synergistically.