Research On The Law Of Water Quality Change And The Application Of Water-Lifting Aerator In Heihe Reservoir

Source water reservoir is different from the general sense of lakes and reservoirs,the biggest difference is that the source water reservoir requires water quality higher,so it is more difficult to control water pollution. However, most reservoirs areconfronted with water pollution problems, some even so serious that not fit as drinkingwater sources. Heihe reservoir is the main surface water source of Xi’an city, researchon migration and transformation law of the water quality and the application ofwater-lifting aeration are meaningful for water resources protection and water pollutioncontrol in the further.We use reservoir monitoring and laboratory analysis to research the law of waterquality change and the application of water-lifting aerator in Heihe reservoir. Thispaper includes the following three main aspects:(1) Research on migration andtransformation law of water quality change in Heihe reservoir;(2) storm-runoffAnalysis on influence of rainstorm in Heihe reservoir;(3) Study on application ofwater-lifting aeration. The major conclusions are:(1) Heihe reservoir belongs deep and layered reservoir, in summer will form astable layer. From July to September the reservoir forms stable stratification. In thisperiod, turbidity and permanganate increase because of the rainfall. From October toDecember the stratification weaken, internal pollution release in the bottom waterbecause of low oxygen. From January to March is the mixing period, at the beginningtime permanganate total phosphorus are increasing, pH value reduces, it is the furtherrelease of pollution substances at the bottom. Hierarchical formation period is fromApril to June, water bodies begin to form stratification. (2) The system study of "water catchment area (upstream)-reservoir-confluence"shows: except the total nitrogen is a little higher at the upstream of Heihe reservoir,other water quality indicators are good, but low load of pollutants entering into Heihereservoir with long-term cause the accumulation of pollutants which will furtherexacerbated Heihe reservoir internal pollution releases. Internal pollution release is stillthe main cause of the deterioration of water quality. Confluence pool water quality isbad than the upstream area and the average value in Heihe reservoir, and affected byupstream flow more obvious, confluence water quality change lag than upstream.(3) Fifty years once heavy rainfall broke the reservoir-original hierarchicalstructure, the upper and lower water temperature reduces5.5degrees centigrade. Thefirst heavy rain causes the middle and up layer water mixed, with the process ofcontinuous rainfall the middle and bottom layer water mixed. During the rainstormperiod, the upstream water brings large amounts of nutrient which cause theaccumulation of pollutants. The increase of raw water turbidity and permanganatecaused by rainfall brings problem to water treatment plant.(4) The water-lifting aeration technologies are flexible and can be appliedaccording to different characteristics of the water, practice shows that the water-liftingaeration technology has good effect on the control of internal pollution release, destroywater stratification, oxygen the anaerobic water at the bottom and algae control.