Location: Cool and Cold Water Aquaculture ResearchTitle: Assessing Peracetic Acid application methodolgy and impacts on fluidized sand biofilter performance
|LEPINE, CHRISTINE - Freshwater Institute
|REDMAN, NATALIE - Freshwater Institute
|MURRAY, MEGAN - Freshwater Institute
|LAZADO, CARLO - Nofima
|JOHANSEN, LILL-HEIDI - Nofima
|ESPMARK, ASA MARIA - Nofima
|DAVIDSON, JOHN - Freshwater Institute
|GOOD, CHRISTOPHER - Freshwater Institute
Submitted to: Aquaculture Research
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/21/2023
Publication Date: 5/8/2023
Citation: Lepine, C.A., Redman, N., Murray, M., Lazado, C., Johansen, L., Espmark, A., Davidson, J., Good, C. 2023. Assessing Peracetic Acid application methodolgy and impacts on fluidized sand biofilter performance. Aquaculture Research. 2023:6294325. https://doi.org/10.1155/2023/6294325.
Interpretive Summary: Recirculating aquaculture systems (RAS) are more sustainable than traditional aquaculture methods, because of their ability to continually recycle and reuse water. Essential to this process is the biofilter, a dedicated place within the system that allows beneficial bacteria, which naturally reduce harmful compounds excreted in fish waste, to thrive. However, during routine treatments meant to reduce detrimental bacteria damaging to fish health, the beneficial bacteria populations can also be harmed. Understanding what treatments are most effective to removing detrimental bacteria while maintaining beneficial bacteria are imperative for farmers to be successful. This experiment examined a chemical, peracetic acid, which is commonly used in European RAS but has not yet been approved in the US for use with food fish. Researchers found that two application methods administered at varying concentrations meant to reduce detrimental bacteria, did not adversely impact beneficial bacteria. Results from this study provide evidence for US regulating bodies that peracetic acid can effectively and safely be used by US farmers.
Technical Abstract: Nitrifying biofilters oxidize harmful ammonia that is excreted by fish into less toxic nitrate within recirculating aquaculture systems (RAS). The biofilter's performance and resulting RAS water quality, largely depends on a robust microbiome that effectively converts nitrogenous wastes. However, occasional use of RAS water disinfectants may also be necessary to reduce or eliminate opportunistic pathogens, such as Flavobacterium spp. Disinfectants and sanitizers such as peracetic acid (PAA) work by disrupting microbial activity, and as such could unintentionally alter the microbially-driven nitrification biofiltration process. Furthermore, the target concentration and application method of PAA may influence the level of biofilter disruption. For this study, 12 replicated experimental-scale fluidized sand biofilters (122 cm high x 15 cm diameter; 22.1 L empty volume) were dosed with PAA to achieve target concentrations ranging from 1.0-2.5 mg/L. Two application methods were compared including i) a single pulse of PAA added every other day for five days, and ii) smaller doses of PAA added every five minutes over four hours. The PAA decay was monitored, and pre- and post-dosing water quality parameters were assessed. Regardless of target concentration or application method, PAA addition within the tested range did not cause significant disruption to the biofilter's nitrification processes.