If aquaculture is to achieve high yield and efficiency, whether in pond culture or factory culture, one of the most basic and important conditions is oxygen enrichment. Aquatic life lives by breathing oxygen dissolved in water. Therefore, dissolved oxygen in water is one of the key indicators for the survival of organisms in water. Generally speaking, 5-8mg/L dissolved oxygen is ok. Some varieties need 10-12mg/L or even higher dissolved oxygen. At present, the state of domestic aquaculture technology it was basically not meet the above requirements, and quite a number of aquaculture products even live in anoxic death, live in such conditions, are often the aquaculture products varieties of degradation, frail, slow growth, but also make the bait, to increase the consumption of water, electricity, medicine, reduces the product quality, increase the production cost.
With sufficient dissolved oxygen in water, the growth and metabolism of fish are vigorous, and the digestion time of feed is greatly shortened. The growth rate index of fish is increasing, and the feed coefficient is negative. Tests have shown that; When the dissolved oxygen in water decreased from 7.6 mg /L to 3.1 mg /L, the feed coefficient increased by 5.6 times, while the growth rate decreased by 9 ~ 10 times. When the dissolved oxygen dropped to 4 mg/l, the fish's food intake decreased by 13%. When the dissolved oxygen dropped to 2 mg/l, the fish's food intake decreased by 54%. When the dissolved oxygen dropped to less than 1 mg/l, the fish stopped eating.
Adequate dissolved oxygen can also improve the living environment of fish habitat, reduce the concentration of ammonia nitrogen, nitrite nitrogen, hydrogen sulfide and other toxic substances. If fish and shrimp live in water with insufficient dissolved oxygen, their physique will decrease, their resistance to diseases will decrease, and their incidence of diseases will rise. PaRASitic diseases are also easy to spread in hypoxic environment.
At the same time, COD and other organic substances in the water, in the process of decomposition need oxygen participation. In addition to these, many bacteria, such as decomposing bacteria (bacillus odontobacillus, bacillus subtilis, etc.) are oxygen consuming. Therefore, maintaining high dissolved oxygen in water is very important for the safety of aquaculture.
In most cases, the most common application of aquaculture is the oxygen addition of nanotubes and fans, and there are also many people in the conditions of soil pond culture, the use of impeller and surge machine oxygen addition. But increases oxygen air, only 21% of the content of oxygen in the air, oxygen is a gas of poorly soluble in water, therefore, under atmospheric pressure, the solubility of oxygen in the water in the air about 8 to 10 mg/L, increases oxygen air operations can make the water dissolved oxygen saturation of up to 80% 90%, the highest water dissolved oxygen concentration is 8 to 9 mg, according to the guangzhou blue spirit aquatic product technology co., LTD., the field experimental data show that, under the condition of circulating water aquaculture, when breeding density higher than 30 kg per cubic metre of air increases oxygen any way can achieve the growth of aquatic animals. It is necessary to add oxygen to water body with pure oxygen.
The content of oxygen in pure oxygen is almost 5 times as much as that in air. The pure oxygen oxygenation method with purity of over 93% instead of air can make the solubility of oxygen in water as high as 50mg/L. Compared with air oxygenation, it improves the concentration and activity of aerobic microorganisms, so that microorganisms can give full play to their role, and the bioreactor water treatment effect will be better. The concentration of dissolved oxygen in water can be controlled easily by adjusting the oxygen flow and pressure.
However, the biggest problem of pure oxygen oxygenation is still the dissolution efficiency. According to our visit to guangzhou lanling aquatic science and technology co., LTD., it was found that most aquiculturists who use pure oxygen to add oxygen to water bodies still use some nano-aerated tubes. After collecting and calculating the volume of bubbles floating up, the true utilization rate of pure oxygen is less than 5%. The remaining 95 percent of the pure oxygen that goes into the air through the bubbles is wasted. In the long run, the cost of using liquid oxygen is surprisingly high! This does not include the use of liquid oxygen and more inefficient components such as gas stones.
Some people also recommend the use of ultrafine bubble generator, yes, ultrafine bubble generator is a kind of equipment can produce "milk water". There are many people in China to do this equipment modification products. Compared with ordinary aeration accessories, the effect is much better. Because the bubbles it produces are about 100 microns across (but a million miles away from nanometers), it's easy to raise dissolved oxygen in water. The utilization rate of pure oxygen also increased significantly. But some of the gas will still escape from the water after sitting for a while. What's more, the power of ultrafine bubble generator is relatively large. For example, a 100-cubic aquiculture pool with a breeding density of not less than 40 kg per cubic meter requires at least a 3KW ultrafine bubble generator. Therefore, the use of ultrafine bubble generator can be considered if pure oxygen is added to oxygen in small water body or ozone is mixed with water for sterilization.
If pure oxygen can be mixed with water in a way to get highly soluble oxygen water, while still ensuring that pure oxygen will not be wasted in a large amount, it will undoubtedly save a lot of cost of pure oxygen. Pure oxygen dissolved oxygen device is born in this need. From this idea to the final mass production into practical goods, lanling paid a high price. From similar to beer production methods, to oxygen cone residual gas recovery, to a variety of jet and other methods. The results didn't seem to work out. Finally, we adopted a new method and conducted several tests in the high-density circulating water farm, and finally succeeded in stabilizing the performance of the product.
Pure oxygen dissolved oxygen apparatus is most suitable for high-density circulating aquaculture. It can not only quickly increase dissolved oxygen in water to the ultra-saturated state, but also keep dissolved oxygen in water at least 7PPM under the condition of high fish culture density. The main reason is that the system is recycled water. Dissolved oxygen is superimposed. Oxygen dissolution ultimately only provides the normal needs of aquatic fish, high utilization rate. So the consumption of oxygen is actually very small. Unlike aquiculture, water with high dissolved oxygen may be discharged from aquiculture ponds without being used by fish. Therefore, the use of pure oxygen dissolved oxygen apparatus in high-density circulating aquaculture is the real realization of the full use of everything.
Contact: Jack Lee
Add: Guangdong guangzhou