ABSTRACT: Peracetic acid (PAA) is a widely applied disinfectant in aquaculture. Knowledge on PAA decay in seawater (SW) is crucial for its successful implementation in SW aquaculture systems. We investigated the decay dynamics of PAA in SW under controlled conditions to assess the potential effect of temperature, salinity and light. We also applied PAA to 22 tanks with post-smolt Atlantic salmon Salmo salar in full-strength SW (33‰) over a realistic range of therapeutic concentrations (0.15-4.8 mg l^-1) to simulate relevant treatment scenarios. The study showed that PAA degrades rapidly in SW. The degradation follows exponential first-order decay with half-lives on the order of minutes to hours. Salinity and temperature significantly affected the decay of PAA, showing a 4-fold faster decay rate in full-strength SW compared to freshwater. The decay of PAA was not significantly related to the nominal concentration of PAA in the concentration range tested. The other 2 active ingredients in PAA products, hydrogen peroxide (H₂O₂) and acetic acid, were found to degrade at a much slower rate. H₂O₂ half-lives in SW were found to range from 15 to 70 h, and minimal acetate was found to be degraded when added to SW. Finally, we compiled published data on PAA decay in relevant water matrices and discussed the potential environmental impacts, mitigation options and future research.

中文翻译：

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海水中过乙酸的衰减及其在水产养殖中的化学治疗潜力

摘要：过氧乙酸（PAA）是在水产养殖中广泛应用的消毒剂。海水中PAA衰减的知识对于在SW水产养殖系统中成功实施至关重要。我们在受控条件下研究了SW中PAA的衰减动力学，以评估温度，盐度和光的潜在影响。我们还在实际浓度范围内（0.15-4.8 mg l ^-1）将PAA应用于22罐装有全强度SW（33‰）的熏鲑大西洋鲑Salmo salar。）以模拟相关的治疗方案。研究表明，PAA在SW中迅速降解。降解遵循指数级一阶衰变，其半衰期为数分钟至数小时。盐度和温度显着影响PAA的衰减，与纯水相比，全强度SW的衰减速率快4倍。在测试的浓度范围内，PAA的衰减与PAA的标称浓度没有明显关系。发现PAA产品中的其他2种活性成分过氧化氢（H ₂ O ₂）和乙酸降解的速度要慢得多。H ₂ O ₂发现在SW中的半衰期为15到70小时，并且发现添加到SW中时乙酸盐的降解最小。最后，我们汇编了有关水基质中PAA衰减的公开数据，并讨论了潜在的环境影响，缓解方案和未来研究。