Ozone (O3) is a strong oxidant, often unstable, easily decomposed into oxygen. In aquaculture, O3 is used for disinfection, reducing turbidity, reducing pesticides and limiting water pollution, helping shrimp and fish grow well.
In nature, O3 is created when there is thunder, in the O3 industry is formed by discharging in normal air or pure oxygen. O3 in water reacts with water immediately, the higher the pH (salty and brackish water), the greater is the oxidation capacity and the nitric oxide (NO2-) oxidation efficiency is higher than that of ammonium (NH4 + ).
When entering the water due to its powerful oxidative capacity, O3 can break down the cell membrane and destroy the enzyme of the microorganism. O3’s ability to disinfect is very broad, including bacteria, viruses, yeasts, molds, and spores. According to the study, the disinfection rate of O3 is 3,100 times higher than chlorine and does not leave residue of toxic chemical residue to the environment. Only the amount of O3 in water (0.1-1 ppm) is 1-2 minutes to destroy 99% of the bacteria in water. O3 is also toxic to fish and shrimp but easily decomposed after 10-20 minutes.
In addition to high disinfection, O3 also inorganic inorganic substances and heavy metals in water such as iron, manganese. In particular, it can easily break down the linkage of loop molecules in plant protection drugs that should be used to remove pesticide residues in water. The use of O3 in seawater can produce some relatively persistent compounds of bromine such as bromine, bromate or hyaluronic acid that are toxic to aquatic animals, but no studies have identified them as toxic. Shrimp, fish.
Application in aquaculture
O3 has an effective application in aquaculture, especially shrimp farms. O3 can completely replace the chlorine used to sterilize the hatchery and treat the water in the tanks. If seawater is high turbidity, it is possible to combine O3 with light chlorine (7 – 15 ppm) to make it in water quickly and effectively disinfect. Using O3 water treatment can replace chemicals, antibiotics, disease limitation, water quality is significantly improved, shrimp larvae grow faster, evenly, improve the quality of breeding. In shrimp culture, broodstock, O3 water treatment helps to limit the disease caused by viruses, bacteria.
For shrimp culture, commercial fish, O3 increase dissolved oxygen, decompose toxins in water (NH3, H2S) and minimize water change. When used, it is necessary to pay attention to the dosage, duration of use and position in the ponds in order to increase efficiency and limit the effect on livestock. O3 gas can be introduced into the suction air of the air blower to produce a small O3 gas bubble to increase the contact area and the suspended time in water helps in effective disinfection.
>> Although O3 technology is effective in aquaculture, but due to the high price, this technology is not widely used but mainly used in hatcheries of shrimp, crabs, sea fish and some shrimp ponds.