First, materials and methods Test facility Bottom filling aeration equipment includes Roots blower, power equipment, galvanized steel pipe, microporous pipe, PVC pipe, valves, timer switch, etc., equipped with water quality testing equipment. The main pipe is galvanized steel pipe or PVC pipe with a diameter of 75 mm. The gas-filled pipe is a micro-hole pipe or a PVC pipe with a diameter of 10 mm. The PVC pipe has a gas-filled hole with a diameter of 0.4-0.6 mm. Install a gas distribution device at the outlet of the blower, or install an exhaust valve on the main pipe of the near blower. Inflatable pipelines are single-pool or multi-pool parallel. There is a valve control between the main pipe and the inflatable tube to facilitate the regulation of the gas volume. Inflatable pipelines are unilaterally arranged or arranged in "feng" type. The micropipes are laid 10 cm from the bottom of the pool, fixed with wooden stakes, and PVC pipes are laid close to the bottom of the pool. 2. Test plan design The effects of different aerobic methods were tested in four groups of shrimp culture ponds in Lhasa Bin, namely microporous aerobic group, PVC aerobic group, waterwheel aerator, impeller aerator, and 1 A group of pond aquarium aquaculture pond oxygenation effect test group. The aeration performance test of the blower with different power configurations was divided into 3 groups. Three ponds were selected to be configured with blower power of 0.1 kW/mu, 0.2 kW/mu and 0.3 kW/mu, respectively. The aeration effect test of the different distance gas pipelines was designed to design the distance between the installation of inflatable pipes for each pond to be 4 meters, 6 meters and 8 meters, respectively. 3. Dissolved oxygen detection and data analysis Dissolved oxygen detection method: In accordance with the "split" method, set up three detection points in the pond, the detection of the water layer into the surface layer, the bottom layer. Two different test points were set up for the oxygen-inflating effect test of the gas pipelines at different intervals, which were the middle of the gas-filled pipeline and the adjacent two pipelines. The test was performed day and night and tested at regular intervals. Dissolved oxygen detection data for each test point in the pond was arithmetically averaged, dissolved oxygen increase value = dissolved oxygen at the end of the test - initial dissolved oxygen. Second, the test results 1. Comparison of oxygenation effects of different oxygenation methods Micropipe and PVC pipe group at night: The pond area is 3 mu, the water depth is 1.5 meters, the length of the micropore tube is 150 meters/mu, the length of the PVC pipe group is 140 meters/mu, and 1 air hole is drilled every 1 meter. Blower power configuration 0.4 kW/mu. Waterwheel aerators and impeller aerators: The pond area is 10 mu, the water depth is 1.5 meters, and the power configuration is 0.75 kW/mu. The test was performed at 22:00 to 1:00 and was tested every 30 minutes. The test results showed that the DO increase values ​​of the microporous tube and the PVC tube group were greater than the DO increase values ​​of the waterwheel aerator and the impeller aerator. The increase in DO at the end of the filling oxygen was significantly higher than that of the aerator, and the micropipe group was slightly higher than the PVC group. Oxygen test during the day was divided into three groups: micropore tube, Pv C tube and impeller aerator oxygenation 3 groups. The three ponds have an area of ​​10 mu, a water depth of 1.5 meters, and a transparency of 25 cm. The blower power configuration is 0.18k kW/mu, the length of the micropipes is 150m/mu, and the length of the PVC pipe is 140m/mu. Every 1m is drilled with 1 inflatable hole and the hole diameter is 0.6mm. The impeller aerator power configuration 0.5 kW/mu. The test is performed at 8:00 to 12:00, once every hour. From the test results, it can be seen that the DO value of the microporous tube group and the dissolved oxygen value of the bottom layer of the PVC tube group are significantly higher than the impeller oxygen aeration unit. 2. Comparison of Dissolved Oxygen in Different Inflation Channel Spacing The trials were conducted on shrimp and pond cultivation ponds in Lifanbin. The distance between the inflatable pipelines of the shrimp culture ponds in Vanuabina is 4 meters, 6 meters and 8 meters respectively. The three ponds have an area of ​​18 mu and a water depth of 1.5 meters. The blower power is 0.28 kW/mu. The test was performed at 14:30 to 6:30 and the dissolved oxygen in the surface and bottom water bodies was measured every 2 to 4 hours. The inflator of the pond crab pond is a PVC pipe with a spacing of 6 meters, a pond area of ​​15 acres, a water depth of 1.5 meters and a blower power configuration of 0.20 kW/mu. Detection of dissolved oxygen was performed every 6 hours at 16:30 to 16:30. It can be seen from the test results that the difference in dissolved oxygen values ​​between the gas pipeline and the two pipelines in the horizontal direction is very small. Except for 10:00, the dissolved oxygen in the vertical direction “water layer difference†is small. The "difference in dissolved oxygen" level between the surface and the bottom of the water in the pipeline is 0.04 to 0.47 mg/l. The aeration effect of the air-filled pipelines with a distance of 4 to 8 meters is basically the same. III. Discussion 1. Evaluation of blower power allocation and aeration effect Different blower power configurations The bottom filling oxygen enrichment effectiveness comparison tests were divided into three groups. The blower power configuration was 0.1 kW/mu, 0.2 kW/mu, and 0.3 kW/mu, respectively. The three ponds have an area of ​​12 mu and a water depth of 1.5 meters. The gas pipelines are microporous tubes and the pipeline length is 150 meters/mu. From the test results, the DO increases in the 0.2 kW and 0.3 kW groups are similar, with surface waters of 6.27 mg/l and 5.98 mg/l, respectively, and the bottom layers are 4.60 mg/l and 5.18 mg/l, respectively. The 0.1 kW group had 2.87 mg/l of dissolved oxygen at the surface and 2.55 mg/l at the bottom. 2. Evaluation of Oxygen Enhancement Effect of Bottom Filling Oxygenation Method The increase in dissolved oxygen during nighttime and daytime aerobic tests did not increase or deduct dissolved oxygen that was produced by water photosynthesis and “water respiration†and was not the net increase in dissolved oxygen by aerators. According to the data analysis of the daytime test, the dissolved oxygen "water layer difference" at the time of bottom-filled aeration was small, and the bottom layer DO increased more than the surface layer, indicating that the bottom-filling method can make good use of the photosynthesis of the upper water body of the pond. Abundant dissolved oxygen, through the up and down movement of water, transported to the bottom layer to quickly increase the dissolved oxygen in the bottom layer, coupled with the role of mechanical oxygenation, the bottom filling oxygenation method is an efficient oxygenation technology. From this, it can be explained why the oxygen efficiency of the bottom-filled aerated method is significantly greater than that of the waterwheel-type and impeller-type aerators. 3. Power configuration of aeration oxygen blower The power configuration of the bottom-filled aeration blower is related to factors such as the water level of the pond, the state of the water environment, the density of the farmed animals, and the aerobic requirements of the farmed animals. Refer to the non-environmental pollution technical specification, set the minimum value of the bottom DO of the pond as 3 mg/L as the critical value, and use it as the basis for the power configuration of the bottom-filled aeration blower. The blower power configuration of 0.30 kW/mu can meet the minimum requirement for dissolved oxygen in the culture pond. Claim. However, taking into account that the main source of dissolved oxygen in the local pond water is the photosynthesis of phytoplankton in the water, the oxygenation at the bottom can make full use of the dissolved oxygen produced by the photosynthesis of the surface layer of the water, and the blower power allocation of the oxygenation at the bottom of the pond at the bottom of the pond is sufficient. 0.20 kW/mu, and the selection of swimming crab ponds with a choice of 0.15 kilowatts/mu can basically meet the requirements for aquaculture water quality. 4. Selection of inflatable pipe and proper spacing of pipe The test results show that the oxygen increase effect of the air-filled pipeline spacing is from 4 meters to 8 meters is basically the same. Taking into account the high density of shrimp cultivation in Lhavana, and the smaller density of the crabs, the distance between the inflatable pipes in the ponds of Lannabinbin shrimp is set at 4-6 meters, and the ponds for pond culture with crabs are set at 8 meters. Using micro-pipes and PVC pipes as inflation pipes, there is no significant difference in the oxygen-enhancing effect of the two. Due to the price difference between the two materials, from the viewpoint of saving investment, ease of use and durability, it is more economical and practical to select PVC pipe as the bottom-filled aerated aeration tube for the production breeding of P. vannamei and portunus. Nicotinamide Nucleotide,NMN Power For Face Cream,Face Cream Raw Materials NMN,Pure NMN Power In Face Cream Yuyao Lifespan Health Technology Co., Ltd. , https://www.yuyaolifespan.com