北京红领巾湖的富营养化状态与水质分析

Analysis on the eutrophication and water quality of Honglingjin Lake in Beijing

红领巾湖位于北京朝阳门外,以再生水为补给水源,在调节湖区小气候、改善周围生态环境、提供居民休闲等方面具有重要功能。2008年3~10月的浮游藻类和理化指标监测结果显示,该湖为重富营养型水体,浮游藻类平均细胞密度为24.73×106个/L,叶绿素a平均质量浓度为84.67μg/L;优势种群是微囊藻（Microcystis sp.）、平裂藻（Merismopediasp.）和栅藻（Scenedesmussp.）,均为重富营养型水体指示种,6~9月出现不同程度的蓝藻水华;TN、TP、COD平均值分别为2.75、0.16、42.16 mg/L,TP超过《景观娱乐用水水质标准》（GB 12941—91）一般景观水质标准（TP 0.05 mg/L）。相关性分析表明,浮游藻类细胞密度与水体中TP的含量呈显著正相关（P〈0.05）。减少湖水中污染物含量、防治蓝藻水华是红领巾湖生态与社会功能得以保持的首要任务。

Water specimens in four sections of Honglingjin Lake were sampled from March 2008 to October 2008 for determination the entrophication and water quality of Honglingjin Lake.The results showed that Honglingjin Lake was at high eutrophication level with the average cell density of phytoplankton was 24.73×106 cells/L and the average amount of Chl-a was 84.67 μg/L.The dominant populations were Scenedesmus sp.,Microcystis sp.and Merismopedia sp.,which were all indicator of heavy eutrophication.Furthermore,different levels of cyanobacteria bloom were observed in the period of June to September.The amount of TN,TP and COD was 2.75,0.16,42.16 mg/L respectively,and the concentration of TN and COD were a little higher than the normal standard of landscape water quality.The correlation analysis revealed that phytoplankton cells was positively correlated with TP and COD with P0.05.Currently,controlling the pollutants emission and cyanobacterial bloom was the primary task for maintain the ecological and social function of Honglingjin Lake.