The Experimental Research Simulating the Eutrophication of the Drinking Water Using the Microcosm Model

According to the characteristics of the climate in northern China,to solve the problems of eutrophication in the drinking water sources,water microcosms were used to model the course of lake water eutrophication under natural condition.The relationship between temperature and eutrophication was studied.Nitrogen and phosphorus concentration were tested week by week to investigate their relationship with the proliferation of algae,respectively.The results showed that: At the range of temperature 22~35℃,algae grows sharply with the temperature rising in 30~35℃.Phosphorus would be the limiting factor of eutrophication only if it be in the initial stage of algae growth;the main factors of affecting the total phosphorus concentration are: the background values of phosphorus in the water,the utilization for the growth of the autotrophic organisms,releasing phosphorus from the sediment.Sediment-water exchange takes the leading role in the phosphorus source.29 species were identified during the process of algea prolification,of which the dominant species are Microcystis,Anabaena-aquae,Aphanizomenon and Tribonema.The percentage of dominant species out of total was rising from 21.95% to 99.20%.With the decline of the algae diversity,the percentage of dominant species increase.