Direct application of ozone in aquaculture systems

Abstract

Ozone (O3) is a powerful oxidant that has been used in both the aquaculture and water treatment industries to improve water quality and reduce pathogens during pretreatment, treatment of effluent, as a continual treatment during RAS operations, and for bivalve depuration. As ozone can be toxic to aquatic organisms, the technology has also been investigated to destroy invasive or nuisance species, and other research has also highlighted negative effects of residual ozone on water courses. Ozone and ozone‐produced oxidants used in aquaculture operations have therefore typically been removed from water prior to entry into tanks holding stock animals. However, a growing body of research has identified direct application of ozone, here defined as exposure of residual ozone and ozone‐produced oxidants to cultured species of finfish, shellfish and live feeds across various life stages. This approach appears to be increasingly employed as a beneficial technology due to proven enhancement of hygiene and water quality, provided dosages or concentrations are appropriate to maintain animal health and welfare. This review paper concentrates on the observed benefits and drawbacks of direct ozonation, influencing factors and future considerations for standardisation and uptake of the technology.

The Rising Tide of Antimicrobial Resistance in Aquaculture: Sources, Sinks and Solutions

“…In addition, the disinfection of system water may be managed with UV application [127] or, as is often the case for intensive systems, via ozone treatment [127,128]. These alternative strategies combined with a better understanding of the effects on the microbiome of the farmed host may provide alternative solutions to improve aquaculture health and function, while reducing the potential for the spread of antimicrobial resistance.…”

Controlling of geosmin and 2‐methylisoborneol induced off‐flavours in recirculating aquaculture system farmed fish—A review

“…Ozonation is a common treatment to enhance the water quality and often used as a disinfectant (Powell & Scolding, ). It is a strong oxidising agent which reacts rapidly with non‐biodegradable dissolved organic matter (DOM), converting it into easier biodegradable molecules.…”

“…In aquaculture, ozone can be used for treatment of incoming water, effluent water or control of circulating water (Powell & Scolding, ). Ozone can be used to inactivate and kill pathogens before entering the aquaculture systems (Summerfelt & Hochheimer, ) or to remove suspended solids, reduce nitrite and non‐biodegradable organic molecules and increase dissolved oxygen (Rahmadi & Kim, ; Summerfelt & Hochheimer, ).…”

“…Ozone can be used to inactivate and kill pathogens before entering the aquaculture systems (Summerfelt & Hochheimer, ) or to remove suspended solids, reduce nitrite and non‐biodegradable organic molecules and increase dissolved oxygen (Rahmadi & Kim, ; Summerfelt & Hochheimer, ). For incoming water, dosages can be relatively high (0.4–0.5 mg/L, oxidation‐reduction potential (ORP) 700 mV) with 5–10 min contact time (Cheremisinoff, ; Powell & Scolding, ). In recirculating systems, ozone can be applied during water treatment and processing to improve the water quality (Davidson et al, ).…”

Use of fluorescence spectroscopy to control ozone dosage in recirculating aquaculture systems

“…The latest are related to microbial activity (Cumberland et al, 2012) and therefore to organic matter bioavailability. Fluorophore name (Coble, 1996) Ozonation is a well-established technology in multiple water treatment applications and has indisputable benefits for water quality (Powell and Scolding, 2016). Furthermore, it is a strong oxidising agent and reacts rapidly with non-biodegradable DOM, converting it into easier biodegradable molecules.…”