Maintaining fish, such as salmonids, in good health in farming systems with water recirculating systems, requires the maintenance of a good quality of these waters. However, even with the use of different methods of treatment, the quality of water in these systems may not be favorable to the rearing of fish. The use of alternative methods to maintain fish rearing water in good quality while protecting the aquatic environment and water resources is necessary. In this context, this study essentially aims to evaluate the effectiveness of ozonation on the water physicochemical quality in fish farms with water recirculating system.
Fish water intakes were made during the different seasons. The results found show that fish waters don’t contain Br- bromide ions and that farmed waters are more polluted than fish fry waters. The application of ozone at a rate of 1.3 ± 0.3 mg O3 / min / L, for 2 hours, has shown that under these conditions the safe reaction time for the fish is approximately 110 minutes while for fry the safe reaction time is about 25 minutes. The addition of ozone effectively reduced COD, BOD5, TC, TIC, alkalinity and dissolved solids. On the other hand, the injection of the ozone led to the increase of pH, the oxidation-reduction potential ORP, the nitrates and the turbidity, but without exceeding the limits tolerated by the fry and the fish. However, ozone application did not affect TOC and TSS.
Globally, ozone has significantly improved the quality of fry water and farmed water, which will generally lead to the increase of the water recycling rate and hence reducing water requirements for fish farming.
| Date | 4 Sept 2019 |
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| Original language | French |
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| Awarding Institution | - École de technologie supérieure
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| Supervisor | Robert Hausler (Supervisor) |
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Saad, S. (Author),
Hausler (Supervisor),
4 Sept 2019Student thesis: Master's thesis › Master in Engineering: Environmental Engineering