Research On Algae Monitoring And Water Quality Changes In Source Water

Since the last centry,with economic growth and the impact of human activities,more and more souce reservoirs gradually developed from nutrition to nutritious.The growth of algae divectly affect the water purification process and the water quality and safety.Xi'an Heihe Jinpen reservoir as the main source of water supply,water quality in the reservoir is completed by the classⅠpart of the gradual changes in indicators for more than a water typeⅢ,and content of algal cell density of the peak more than 17 million / L.Therefore,take the Heihe reservoirs as typical water reservoir,reserch on algae growth dynamics and its impact on water quality has important theoretical and practical value.Combination of live-line monitoring and sampling laboratory monitoring, analysed phytoplankton and other water quality indicators of Heihe Jinpen reservoir. The main conclusions are as follows:(1) April to May and June to December are the two characteristics of algae growth phase.In the previous stage,with the water temperature increasing,the number of species increased rapidly,water temperature and algae showed good correlation, the dominant species are the green algae and diatoms;while the latter stage,The number of algae reduced first and then increased due to the effects of light.The peck value amount appears in the mid of July,which dominant species are the green algae and Cyanobacteria.The ratio of nitrogen and phosphorus is between 18-56,this make high TN/TP value which shows that Nitrogen is axcessive and Phosphorus is the restrictive factor.The peak value of alage amount is influenced by the concentration of Phosphorus,water temperature and light.Monitoring instructions appear nutritious phytoplankton population-based,such as Scenedesmus,Microcystis aeruginosa, Chlorella,such as Melosira.(2) Heihe reservoirs in the summer heat stratification,surface and bottom water temperature difference of almost 20℃,water depth of 30-40 m for the thermocline.In spring and autumn,water temperature stratification is not a very significant change,there is no typical "thermocline," but on the vertical profiles of water temperature "on the high low" of the hierarchical structure remains.This effectively limits the temperature stratified water masses of mixed up and down to form a stratified dissolved oxygen,making the lower body of water become anaerobic zone.The results show that the library-site monitoring of cardiac anaerobic bottom water Dissolved oxygen concentration:1mg / L,ammonia nitrogen,total nitrogen and total phosphorus content in surface water were 15 times,3.16 times and 6 times in summer.(3) Water quality in the reservoir area and upper reaches of the Heihe River area shows that the upstream water quality and water quality of the library the same trend of seasonal changes,However,the upper reaches of the reservoir water quality indicators such as the main nitrogen,total nitrogen,total phosphorus and potassium permanganate index in both countriesⅢwater quality standard of surface water,and water quality objectives in the reservoir area were higher than the upstream water quality.Analysis,the water qualty of upper reaches has affect to Heihe reservoir,but the reservoir water quality is mainly due to pollution caused by endogenous.(4) Characteristics of suspended algae and inhibit the growth of pilot experiments show that cyanobacteria ultimately suspends between double and triple of water transparency depth,while chlorophyta ultimately suspends about 0.5 times of water transparency depth..The cyanobacteria was well-distribution and the cyanobacteria under the water transparency had no rising phenomenon when counter-current velocity of water is about1.5 cm/min.The cyanobacteria in surface is decreased by 21.03%,and the cyanobacteria of water transparency depth is decreased by 31.09%at 1.5cm/min when running 12 hours at daytime.