Release Of Nutrients, Sediment In Shallow Water South Of The Reservoir And Its Relationship With The Algal Growth

Reservoir is one of the important modern city drinking water, water quality is good or bad for the development of safe drinking water and aquatic ecosystems play an important role.Sediment at the bottom of lakes and reservoirs and other water bodies for many years accumulation of substances, pollutants in sediment release has a direct impact on the overlying water.Through the survey of water and sediment in cascade reservoir of south China, It finds endogenous phosphorus becomes the main causes algae outbreak in the reservoirs. Analyzing the data, sediment pollution of Sediment A is most serious but it is lighter in Sediment C.Throng control the change of single environment factor to study release law of total nitrogen and total phosphorus containing in sediment, it concludes higher temperature can accelerate the release of total nitrogen and total phosphorus. Anaerobic conditions can accelerate the release of total nitrogen and total phosphorus but aerobic conditions inhibit the release of total nitrogen and total phosphorus. When decreasing of the pH, the release of total nitrogen and total phosphorus can increase. Illumination enhancement can accelerate the release of phosphorus, but it has little effect on the release of total nitrogen.Using the enclosure experiment, sediment nutrient release rule of shallow area of reservoir was studied under the simulated natural condition, the relationship between the sediment nutrient release and the algae growth was also analyzed. The results showed that sediment nutrients in reservoir shallow area started to release on the tenth day and release peak occurred on the seventeenth day. Meanwhile, the sediment nutrient release can acceleratealgae growth. Original overlying water with low concentration can accelerate the release of sediment nutrient and the outbreak of algae comparing with high concentration overlying water. Raining also could accelerate the sediment nutrient release and the growth of algae,especially green algae. Before the algal bloom the pH and dissolved oxygen will raise and appear peak.