Phosphorus Release Mechanism Of Cyanobacterial Blooms And The Contribution Of Cvanobacterial Blooms Withering To Phosphorus Concentration In Caohai Bay Of Lake Dianchi

The occurrence of cyanobacteria bloom has greatly restricted the utilization of lake resources,hindered the sustainable development of social economy,and will affect the safety and health of drinking water.Up till now,cyanobacteria bloom has been an urgent problem to be solved.The release of phosphorus from algae during the disappearance of cyanobacteria bloom is an important link in the eutrophication of the lake,which may play an important role in the formation of a new round of algal blooms.This paper takes Dianchi Lake as the research object,study the different effects of environmental factors on release of phosphorus mineralization of cyanobacteria bloom in Dianchi lake after the death,by means of artificial indoor conditions and field conditions in situ simulation test that extinction of cyanobacteria bloom in Dianchi Lake in Dianchi lake of phosphate residues release characteristics of water available phosphorus contribution,deepen the understanding of water algal bloom phosphorus mineralization and release of phosphorus cycling in eutrophic lakes in effect,provide a theoretical basis for the control of lake eutrophication problem.The main results are as follows:1.The research object of the cyanobacteria water collected by Caohai in Dianchi Lake,using BG11 liquid culture on the condition of illumination cultured indoors,the determination of the content of phosphorus in water and algae,and the content of extracellular polysaccharide,and the analysis of the data in depth,the effect of ph and temperature on the form,phosphorus release and release rate of the phosphorus.The results showed that there was no significant correlation between the different ph value and the concentration of the phosphorus release of algae in different temperature conditions.The ph value and temperature do not affect the release of phosphorus in the process of algae decay,phosphorus release is related to the phosphorus content stored in the initial algae,but the lower pH and higher temperature can accelerate the release rate of phosphorus.2.Using indoor artificial water simulation and field mesocosm experiment,determination of the experimental system of each period of redox potential,conductivity,pH,temperature,chlorophyll a,total phosphorus,total phosphorus,total phosphorus,algae and algae in Minaka Masa is phosphorus,phosphorus in algae,the total extracellular polysaccharide,soluble extracellular polysaccharide and fixed extracellular polysaccharide and other indicators,data statistics and analysis,to explore the regularity of phosphorus release in Dianchi lake.The results showed that the phosphorus in algae was mainly in the form of orthophosphate and organic phosphorus,but not in the form of phosphate.In the process of algae decay,the release of phosphorus from algae cells is mainly released in the form of orthophosphate.Total phosphorus and algae and algae within the rate of phosphorus is the decomposition of extracellular polysaccharide decomposition rate significantly related to phosphorus release process showed that the death of algae is the algae cell outer sheath is destroyed,and the concentrations of phosphorus was released into the water.There was a significant negative correlation between the total phosphorus release rate and the redox potential of algae.The process of phosphorus release from algae belongs to the first order reaction kinetics;3.The relationship between Dianchi Caohai field sampling were established in the winter of chlorophyll a and phosphorus concentration,through satellite remote sensing inversion of Dianchi Caohai overall chlorophyll a distribution and chlorophyll-a and the average concentration of a,and get the contribution to water bloom demise by calculating the amount of phosphorus in summer and winter difference,so as to obtain the release of phosphorus from extinction of cyanobacteria the phosphorus concentration contribution value.The estimation results show that in the 2016 year of Dianchi Lake cyanobacteria bloom in summer phosphorus content of 7.33 tons in winter,phosphorus content of 0.23 tons,7.10 tons of phosphorus release to the water and sediment,which is in the form of phosphate phosphorus release amount was 4.79 tons.In Dianchi,the potential contribution of algae bloom to phosphorus concentration in water was 0.2819mg/L,0.1904 mg/L,and the concentration of organic phosphorus and phosphorus particles was(mg/L).The release of Dianchi Lake cyanobacteria bloom.Phosphorus in winter can not be ignored,can provide sufficient guarantee to maintain the nutritional status of cyanobacteria bloom.