Investigation And Bioremedication Of Hongze Lake Entrophication

Entrophication is a phenomenon that lakes change gradually from poor nutrition and less productivity into rich nutrition and high productivity under the effect of anthropogenic activity. Lakes in nature have their own process of origin and development. Under the influence of excessive content of nutrition elements such as nitrogen and phosphate, lakes will lose their capaci ty of self-puri fication and their environmental balance. Usually entrophication wi; cause great harm to the ecosystem and resources of lakes and impair human life and activity.Many methods have been used to protect lakes. This report deals with the entrophication of Hongze Lake. Hongze Lake is one of the greatest freshwater lakes in China. The data obtained in 2000 showed that water quality of Hongze Lake was beyond grade V according to the Surface Water Hnvironmenttal Quality Standard (GBZB1-1999). Studies on nourishment salt, phytoplankton, chlorophyl a, and acteriology etc indicated that the water quality of Hongze Lake is in the state of mid-entrophicat ion, equaling to the level of 1990s. Apparently the exasperate of water quality of Hongze Lake had been effectively controlled. Hongze Lake is a kind of lake with muddy water, therefore it has come into being the special balance of nature of the Hongze Lake. Based on the water qual ity data obtained from 1998 to 2000, the key entrophication factors of Hongze Lake were suspended substances and diaphaneity. These results showed that the total phosphorus was the potential limited nutrient of entrophication. The effective methods of controlling the lake outrophication (control 1 ing nutrients, killing algae, biomanipulation, and ecological restoration etc.) are suggested by the author.