Study On Driving Mechanism Of Algae Growth In Small Artificial Lake Under Light-nutrients Interaction

The analysis of the growth mechanism of phytoplankton in water is the basis of the study of the principle of eutrophication,and eutrophication is the focus of water environment.According to the geographical conditions of water resources distribution in China,there are few rivers and lakes in the northern region,resulting in the lack of connection between water areas.Moreover,the flow of rivers is small,and the population density of China is large,so the water in the living area is prone to eutrophication,and the eutrophication of the water is not easy to control.There are abundant water resources in the south of China and frequent connections between water areas.However,due to the needs of social and economic development and the lack of awareness of water resources protection before,there are many water quality deterioration and eutrophication.In order to control eutrophication of water body,it is necessary to understand the influence of various factors on the growth of phytoplankton in water body,analyze the influence degree of different factors on the growth of algae,and then make a reasonable water quality control plan.Small lakes are prone to eutrophication under the condition of slow water flow,so this study focuses on the driving mechanism of different influence factors on algae growth in small lakes to determine the impact of different influence factors on algae growth.This study mainly focuses on the driving mechanism of light intensity and the effect of nitrogen and phosphorus nutrients on algae growth.The research contents are from two aspects.One is to carry out the indoor algae culture experiment,which takes the small artificial lake water as the culture water sample.Before the experiment,the content of total nitrogen and total phosphorus in the water was measured,and six kinds of culture scenarios were set up,including different concentrations of nitrogen and phosphorus nutrients,different concentrations of phosphorus nutrients,simultaneous changes of nitrogen and phosphorus nutrients,and three kinds of lighting conditions: natural light,indoor light and no light.Finally,according to the concentration of chlorophyll a and phycocyanin under different conditions,the driving mechanism of algae growth was analyzed.On the other hand,a model is designed to simulate the growth and change process of algae in Meihu lake,and various scenarios are also carried out to simulate,and the optimal nutrient concentration and light intensity suitable for algae growth are identified.According to the indoor experiment results and model simulation results,the influence degree of different light and nutrient concentration on the algae growth process was analyzed,and the contribution rate of light intensity,nitrogen and phosphorus nutrients in the algae growth process were quantified.