Research On Oxygen Restoration Experiment Of FoShan Creek And Its Distributaries

According to the pollution of Foshan creek and its distributaries, using the domestic and foreign creek re-obtain oxygen technology and oxygen transfer theory as reference, through done the oxygenation test and simulative test in clean water & polluted water, the thesis has assessed the efficiency of artificial re-obtain oxygen. The calculation of the academic & experimenced value of oxygen demand of Foshan creek and its distributaries as well as the assessment of the functions of different kinds of re-obtain oxygen technology provide the theory and experimental elements for Foshan creek re-obtain oxygen projects' design and operation. The effective approach of water environmental ecology rehabilitation was also explored in this thesis. Following works have been carried out: (1) According to the clean water static oxygenation test, the oxygenation capability of different oxygen source has beeb estimated in the thesis, different aerators and different water depth. Among different aerations, the fine bubble aeration is the most effective way, which has upper oxygen-transfer efficiency of 2.66 kgO2/kW·h, which is 1.63 times more than shooting flow aeration at the same water depth. Oxygen utility ratio of fine bubble aeration is the highest that is 25.7%, which uses pure oxygen as source. According to the integrated analyse of technology and economy, fine bubble aeration using air as source be considered first in project application; (2) According to the polluted water static oxygenation test, the oxygen transfer coefficient of different aerators and different water depth has been modified, modificatory coefficient of oxygen transfer (α =0.34) & modificatory coefficient of saturated oxygen ( β =0.94) were then obtained; (3) According to the comparison test of all kinds of oxygenation and simulative test of artificial re-obtain oxygen of Foshan creek, the thesis has estimated the functions of artificial re-obtain oxygen. The removal rate of COD_Cr is the highest when using fine bubble aeration, which is direct ratio to oxygen amount. The removal rate of COD_Cr is between 17.7% and 18% and the average is 17.86%. (4) The calculating method of oxygen demand of Foshan creek and its distributaries has beeb studied in the thesis, then validated the calculating method by experiment. The calculating results is that the academic oxygen demand of Foshan creek is 24.20tO2/d and the academic oxygen demand of thirteen distributaries is 22.85tO2/d. The experiential oxygen demand of Foshan creek is six times more than the academic oxygen demand. The innovation of the thesis are: the test chooses fine bubble aeration as aerator, which is used in creek re-obtain oxygen for the first time; the test utilizes the relation curve of air-water ratio and dissolved oxygen to deduce creek experiential oxygen demand.