Lakes and Reservoirs Research

Hypolimnetic oxygenation of stratified reservoirs

Faculty Member: Dr. John Little

Hypolimnetic water in stratified reservoirs may become depleted of oxygen under certain circumstances, with potential negative consequences for water quality. One remedial strategy is to replenish the oxygen using hypolimnetic oxygenators. We are developing comprehensive process models for the three most common systems: the Speece Cone, the bubble-plume diffuser, and the full-lift hypolimnetic aerator to enable efficient design and optimal operation of hypolimnetic oxygenation systems. We are also coupling the hypolimnetic oxygenation models with a 2-D reservoir model to further optimize performance and to investigate the impact of the systems on mixing and dissolved oxygen distribution within a reservoir.

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Contour plot (oC) showing measured thermal structure of large bubble plume in a deep lake as well as the model predicted plume diameter.


The Impact of Salt Fluxes on Meromixis in Lakes

Faculty Member: Dr. John Little

S_lakes_reservioirs_research2Our research goal is to develop a model that simulates the conditions that induce or eradicate meromixis in lakes, thereby establishing the prevailing redox conditions in the water column. Because the salt accumulation cycle is relatively complex we are using salinity data to calculate salt fluxes that can be incorporated into a 1-D hydrodynamic lake model. This seich-extended, k-epsilon model has proven to be especially effective at predicting vertical turbulent diffusivity during stratified periods and is therefore well suited for simulating the conditions surrounding meromixis. Once this model has been developed and verified, it will be used to quantify the effect of wind, temperature, primary productivity, and river inflow on meromixis.