水源地水体富营养化过程微宇宙模拟试验研究

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

针对北方气候特点解决湖库水源水富营养化问题,构建了水生微宇宙模型模拟自然环境下水源地水体富营养化的过程,研究了温度和富营养化的关系、总磷的变化规律与藻类增殖的相关关系,考察了富营养化不同阶段藻类演替规律及优势种属变化趋势。研究表明,在22~35℃时,藻类随温度升高生长速度加快,在30~35℃时比增殖速度升高极快。富营养过程中,磷只在富营养化初期是藻类生长的(限制)决定因素;影响水体中总磷浓度的主要因素有三个:水体中磷的本底值、自养生物生长利用和底泥的释磷作用,而底泥和水体交换起主导作用;富营养化藻类增殖过程中共鉴定出藻类29属,藻类种属数先升高后下降,由最初的13种增加到24种最终下降到7种,最后确定水华优势藻属为微囊藻属、水华鱼腥藻、束丝藻属和黄丝藻属。随着藻类增殖,藻属数逐渐减少,水华藻类的优势明显,占藻类总数的比例由第2周的21.95%上升到第16周的99.20%,浮游藻类的物种多样性减退,优势种的比例增加。

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.