Process optimization, advanced control, and computational fluid dynamics modelling of wastewater disinfection using peracids

In this presentation, we will illustrate innovative concepts for advanced dose control and best methods of practice for the evaluation of municipal wastewater disinfection using peracids (e.g., peracetic and performic acid). To assess the benefit of CT-based PAA dose control, simulations were performed to quantify the PAA required to achieve an E. coli disinfection target of 500 CFU / 100 mL for a plant over a 20-day period. The flow variations from real plants were utilized in order to capture both diurnal variations as well as wet weather events. The disinfection contact basin was sized to achieve a ~30 min HRT at average daily flow. Simulations were performed where the PAA dosing was controlled by concentration-set point-flow-paced control versus CT-set point-dose-paced control. It was observed that the CT-based control technology was superior to ensuring constant microbial effluent quality leading to substantial savings for plants with high peak factors in flowrate, such as the ones occurring during wet-weather events.