Correction of water acidity and the concentration of dissolved oxygen in water in the recirculating aquaculture system

The article presents the results of a research of the rate of change in the pH level and the maximum pH values when soda is added to distilled water and water from fish production. The dependences of the change in the concentration of dissolved oxygen in water on the change in the volume of supplied air are obtained.

Introduction. The most important chemical parameters of water in recirculating water supply installations are the level of water acidity and the concentration of oxygen dissolved in water. They have a significant impact on the growth and development of fish and require special attention. During stable operation, the system can independently maintain the pH level, but if emergency situations occur, the water can change the pH in an acidic direction to values dangerous for fish. Baking soda can restore the optimal PH level during acidification. It not only makes it possible to raise the pH to the alkaline side, but also increases the productivity of biological filters. The oxygen concentration is constantly maintained using oxygen generators, which saturate the water with oxygen. To control the oxygen supply system to water, it is necessary to have information about the dependence of changes in the concentration of dissolved oxygen on the volume of supplied air.

Object. Chemical parameters of water in closed water supply installations.

Materials and methods. Studies have been carried out to determine the rate of change in water pH and its maximum value. During the study, distilled water and water from closed water supply installations were used, and air was supplied to it to simulate the process of bubbling water. The study of the process of water saturation with oxygen depending on the volume of air supplied per unit time took place in two stages. At the first stage, the required speed of air supply to the water was established. And on the second, the process of measuring the concentration of oxygen dissolved in water took place.

Results and conclusions. The dependence of the change in pH of distilled water on time was obtained for different masses of added soda. It has been established that the process of pH growth, depending on the increase in soda concentration, occurs faster in distilled water than in water from closed water supply systems. A study of the process of water saturation with oxygen showed that an increase in the aeration rate leads to an increase in the maximum oxygen concentration in water and a decrease in the time to reach the maximum oxygen concentration.

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