Mechanisms and potential for disinfection byproduct formation from peracetic acid

Peracetic acid (PAA) has emerged as a promising alternative to free chlorine for achieving high-level disinfection in combined sewer overflow, wastewater, and stormwater. However, a major concern with any water disinfectant is its potential to react with natural organic matter or other constituents, leading to the unintentional formation of disinfection byproducts (DBPs). This review examines DBP formation during PAA disinfection and PAA-based advanced oxidation processes (AOPs), with an emphasis on studies published within the past five years. It summarizes the influence of halides, nitrite, and various AOP operational conditions on DBP formation. Additionally, it explores the mechanisms of DBP formation in the presence of halides during PAA disinfection, highlighting key intermediates involved in the reactions. The insights provided in this review offer valuable guidance for minimizing DBP formation in further applications of PAA in water treatment.