The Impact Of Aerator Perturbations On Temporal And Spatial Distribution Pattern Of Suspended Matter And Dissolved Oxygen Of Pond Water

The aerator is commonly used in aquaculture. The successful development and application of impeller aerator contribute a lot to China’s ponds yield. This paper concentrates on the impact of aerator operation on spatial and temporal distribution of suspended matter and dissolved oxygen of pond water to accumulate data for the development of the mechanical application of fisheries and pond aquaculture industry. The main results are as follows:1. In the research for spatial and temporal distribution of suspended matter within the24hours of the day. When the aerator is out of work, the results show at8:00and12:00these two sampling time, all the suspended matter concentrations are similar. From12:00to14:00, the concentration trends are downward. From14:00to3:00of the next day, they are stable. The next day between3:00and8:00, they are upward with a huge range. When the impeller aerator is on, the total concentration of the suspended matter show an upward trend. The point which is2meters away from the pond center shows the largest increase, much higher than other places. When the impeller aerator is out of work again, it shows a downward trend between14:00and22:00. All of the points show similar suspended matter concentration before the biofan is running. When the biofan is running, between12:00and14:00all the concentrations of the suspended matter show an upward trend. The point which is2meters away from the pond center shows the largest increase, much higher than other places. Between14:00and18:00, the2m point is still upward when other points are downward. Between18:00and22:00the2m point drops the most seriously. From22:00to8:00of the next day, all the total concentration levels are stable.2. In the experiment aiming at suspended matters during the aerator’s running process, except the16m point, the changing trends of four different depths of all other points are similar, that is, up first then down then up again. But the changing scope and time range are a little different. During the biofan running process, the concentrations of different distances and different depths show a similar changing trend too. In the first20min, the concentrations of the two points near the water-sediments decline when the two near water-air rise. Between20min and40min, all the four depths points are rising,40-60min, declining;60-90, rising and90-120min, declining. But the accessional and decreasing ranges of different places are various. 3. In the research aims at the spatial and temporal distribution of dissolved oxygen within the24hours of the day. Before the impeller aerator works, there is an obvious layering phenomenon at each sampling point. After the aerator runs two hours, the dissolved oxygen levels of the four depths at2m,6m and11m points are close to each other. Before the biofan works, there is an obvious layering phenomenon at each sampling point. After the aerator runs two hours, the dissolved oxygen levels of the four depths at2m and6m points are close to each other. However the layering phenomenon still exists at the four places which are far away from the pond center.4. In the experiment aiming at dissolved oxygen during the aerator’s running process, the result shows that dissolved oxygen levels of2m,6m and11m points are similar after the aerator running for two hours. The detail changing trends are as follows:20-90min after the aerator is on, all the dissolved oxygen amounts are falling;90-120min, all are going up. When the biofan is working, all are rising first (0-40min), then dropping (40-90min), then ascending (90-120min) but with various fluctuation range. After the biofan runs for20minutes, dissolved oxygen levels of the four depths of2m points are similar.