Disinfection by peracetic acid: influence of inorganic and organic compounds

The disinfection effectiveness of peracetic acid (PAA) for wastewater applications has been extensively documented; however, PAA decays rapidly in water solution, depending on the water matrix characteristics. Guarantying a proper disinfectant dose is fundamental for the design of a disinfection process, therefore modeling PAA decay as a function of wastewater characteristics is crucial. The aim of this study was to assess PAA consumption in multi-component solutions reflecting realistic situations of a final effluent of a wastewater treatment plant (WWTP) under controlled conditions. Two experimental plans, one for inorganics and another one for organics, were defined using the statistical method of Design of Experiments (DoE), which allowed evaluating the effect of each compound or their interaction on PAA decay. Experiments were performed at laboratory-scale for PAA concentrations between 2-10 mgPAA/L and linear least-square regressions were used to interpolate two models based on the compounds that displayed an effect on PAA decay.