PAA – An Alternative for Wastewater Disinfection: Engineering and Cost Considerations

With uncertainty regarding future requirements for chlorine gas and potential challenges with chlorinated disinfection by-products (DBPs), wastewater utilities are proactively evaluating options to replace chlorine with other disinfection alternatives. Ultraviolet (UV) disinfection has gained in use, but there can be challenges with implementation; such as high capital costs for facilities with high flow peaking factors and the ability of UV to provide consistent disinfection performance for effluents with low UV transmittance or total suspended solids that frequently exceed 20 mg/L. A relatively new alternative to the United States (U.S.) municipal wastewater market is peracetic acid (PAA), a chemical oxidant that has been applied in the food, beverage, medical and pharmaceutical industries as a disinfectant. This paper describes methods to evaluate the feasibility of and design considerations for application of PAA for disinfection to meet National Pollutant Discharge Elimination System (NPDES) permit compliance in recent case studies.