The Strategic Techniques of the Control of Nutritional Elements in the Water Supply

Four strategic techniques of the control of nutritional elements are selected for this study: artificial destratification by the bubble plume, partial (or total) lift hypolimnetic aerator, bubble plume oxygenation and Speece Cone oxygenation. Each of these methods has its advantages and inconveniences. A technical and economic analysis established by different researches reveals that the hypolimnetic oxygenation is the most favorable for the control of nutrional elements. In hypolimnetic aeration systems, the aeration system by bubble plume appears to be the most economic and perhaps the most simple among the systems used in Standley lake (Colorado, U.S.A), even as other researches select Speece Cone aeration system. On the base of these researches, this study makes a state of synthesis on a number of issues related to the aeration in lakes and reservoirs, including the advantages and the inconveniences of these aeration systems. As well, this study concentrate on the economic and technical sides associated to these aeration systems. We found that the aeration by oxygen limits the nitrogen saturation and in contrast the aeration creates it. We demonstrate that the most efficient hypolimnetic aeration system is the bubble plume diffuser; although an accidental destratification may occur. We show as well that the destratification can be used in winter because the temperature of the lake is not modified. However, the hypolimnetic aeration is used in summer in order to avoid the homogenization of the lake temperature during this period.