Title: Peracetic acid degradation in freshwater aquaculture systems and possible practical implications Authors
|Pedersen, Lars-Flemming -|
|Meinelt, Thomas -|
Submitted to: Aquacultural Engineering
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: May 23, 2012
Publication Date: March 10, 2013
Citation: Pedersen, L., Meinelt, T., Straus, D.L. 2013. Peracetic acid degradation in freshwater aquaculture systems and possible practical implications. Aquacultural Engineering. 53:65-71. Interpretive Summary: Peracetic acid (PAA) is an antimicrobial that is being considered as an alternative to formaldehyde as a disinfectant in aquaculture; however, little research is available on its use in aquatic systems. These studies were designed to evaluate how organic matter and temperature can cause PAA to become less effective. Increasing organic material in the water and increasing temperature were both found to cause a much faster decay rate and PAA half-lives were only a few minutes. Trials from several fish farms demonstrate similar effects of organic material and temperature. Additionally, PAA does not give off any residues that harm fish and it degrades rapidly. Recent investigations of PAA use in aquaculture are briefly reviewed and practical implication and guidelines are addressed. The results underscore the importance of understanding the relationship between the efficacy of PAA and the rearing environment. Understanding this relationship will provide fish farmers a safe and effective tool to combat fish diseases thereby substantially increasing crop productivity.
Technical Abstract: Peracetic acid (PAA) is a highly reactive peroxygen compound with wide-ranging antimicrobial effects and is considered an alternative sanitizer to formaldehyde. Products containing PAA are available in solution with acetic acid and hydrogen peroxide to maintain the stability of the chemical, and it decays rapidly when applied to aquaculture system water. The rapid decay is beneficial in an environmental context but a challenge to aquaculturists. To assess the impact of organic matter content and temperature on PAA decay, twenty-four batch experiments were made with PAA doses from 0 to 2.0 mg/l. Increasing organic matter content significantly facilitated PAA decay, and positive temperature-decay correlations were found. Instantaneous PAA consumption above 0.2 mg/l was observed, and PAA half-lives were found to be in the order of a few minutes. The relative PAA recovery, calculated as measured PAA concentration over time compared to the PAA concentration applied, decreased with declining dose. Measurements of PAA residuals during water treatment scenarios at three different freshwater fish farms reveal substantial PAA consumption, stressing the fact that a large discrepancy occurs between delivered quantities and realized residuals. Recent investigations of PAA potential in aquaculture is briefly reviewed, and practical implication and guidelines are addressed.