湘江长沙段浮游植物区系组成及水质评价初步研究

运用指示生物方法,通过调查湘江长沙段浮游植物区系组成,并结合总氮(TN)、总磷(TP)等理化指标分析,对湘江长沙段水质评价进行了初步研究.主要结果如下:湘江长沙段3个样点的水体中共鉴定出浮游植物6门43属61种.浮游植物在区系组成上以硅藻(Bacillariophyta)、绿藻(Chlorophyta)和裸藻(Euglenophyta)3个门为主,优势种类主要有硅藻门的直链藻(Melosira)、菱形藻(Nitzschia)和小环藻(Cyclotella),绿藻门的衣藻(Chamydo-monas),裸藻门的绿色裸藻(Euglena)等.所有采样点的总氮、总磷质量浓度均超过富营养化指标.指示生物评价方面,藻商评价结果显示湘江整体上属富营养型;污染程度分带评价显示湘江长沙段整体达到α-中污和β-中污水平.此外在湘江各样点鉴定出多种耐有机污染和耐重金属污染藻类,显示江水受到有机物,很可能也受到重金属镉、锌和铜等的污染.研究结果表明运用指示生物方法来评价湘江水质具有一定的实际应用价值.

Phytoplankton Flora Composition and Water Quality Evaluation of Xiangjiang River in Changsha

The phytoplankton flora composition of Xiangjiang River in Changsha was studied by using biological indicator method,and with the total nitrogen(TN),total phosphorus(TP) and other physicochemical indexes.There were 43 genera and 61 species of phytoplankton belonging to 6 phyla in Xiangjiang River of Changsha;the dominant phyla are Bacillariophyta and Chlorophyta and Euglenophyta,and the dominant species are Melosira and Nitzschi and Cyclotella of Bacillariophyta,Chamydomonas and Pediastrun Meyen of Chlorophyta,Euglena of Euglenophyta.The total nitrogen(TN) and total phosphorus(TP) of all sampling sites exceed the eutrophication index.By using biological indicator,the water quality evaluation results shows that the water of Xiangjiang River is eutrophic,and by using saprobic system,the pollution level of Xiangjiang River is α-mesosaprobic zone and β-mesosaprobic zone.In addition,a variety of algae which can tolerate organic pollution and heavy metals pollution showed that Xiangjiang River was polluted by organic pollutants,and probably by heavy metal cadmium,zinc and copper.Overall the results showed that it is practicable by using biological indicator method to evaluate water quality of Xiangjiang River.