生物浮岛对长湖水质和浮游植物的影响

EFFECT OF BIOLOGICAL FLOATING ISLAND ON WATER QUALITY AND PHYTOPLANKTON IN LAKE CHANGHU

为探索治理长湖水体富营养化的有效方法,开展生物浮岛对其水质和浮游植物的影响。结果表明,在藻类大量生长的季节（7—9月）,浮岛区水体中TN_w、DO、TSS、Chl-a含量以及TLI值较对照区有所下降,下降幅度在6%~62.3%,其中以Chl-a含量下降最明显;浮岛上下游区域浮游植物优势类群存在差异性,而且下游的浮游植物细胞丰度、均匀度指数和Shannon-Wiener多样性指数均较上游有所下降。由此可见,生物浮岛能有效吸附长湖水体中N、P等营养元素,对其藻类水华的爆发具有抑制作用,可作为长湖水体原位生态修复的有效手段。

In order to explore an effective method for controlling the water eutrophication of Lake Changhu,the studies about the effect of biological floating island on the water quality and phytoplankton of lake-bay were carried out. Results showed that：During the algae growing season（from July to September）,the contents of TN_w,DO,TSS,Chl-a and TLI values in the floating island area declined in a range from 6% to 62. 3% compared with the control check area,while the decline of Chl. a reached a significant level; differences existed in the dominant species of phytoplankton between the upper part and lower part of the floating island; compared with the upper part of the floating island,cell abundance,evenness index and ShannonWiener index of phytoplankton in the lower part of the floating island declined in a certain degree. Thus,the biological floating island could adsorb effectively water nutrients such as nitrogen and phosphorus,and inhibit the algae bloom in Lake Changhu.It can be considered as an effective and feasible method of in situ ecological water restoration in Lake Changhu.