Salinity, dissolved organic carbon and water hardness affect peracetic acid (PAA) degradation in aqueous solutions

Peracetic acid (PAA) is used in aquaculture under different conditions for disinfection and therapeutic purposes. There is limited information about its environmental fate, particularly its persistence in aquatic systems with different physical-chemical conditions. This study investigated PAA-degradation of three commercial products, Wofasteril® E400, Wofasteril® E250 and Wofasteril® Lspez, at a nominal concentration of 1 mg L−1 in relation to two levels of salinity, water hardness, or dissolved organic carbon (DOC). The results showed that salinity and DOC stimulate PAA-degradation, while water hardness had only minor impact. For commercial aquaculture, actual PAA concentration in the raw product needs to be measured; the fate of PAA in individual facilities must be carefully monitored and feasible application strategies need to be investigated to achieve maximal disinfection and therapeutic efficiency.