Reviewing the Operating Objectives of the TVA Reservoir System
Under the Tennessee Valley Authority's Lake Improvement Plan, approved by the Board of Directors in February 1991, minimum flows will be provided systemwide, the releases...
Effect of Temperature on Gas Transfer at Low Surface Renewal Rates
In order to investigate the dependence of gas transfer coefficients on temperature under conditions of low surface renewal rates, laboratory experiments were conducted using simultaneous...
Turbulent Water Aeration: Analytical Approach and Experimental Data
Analytical studies based on the statistical theory of turbulence were carried out in order to identify some relevant parameters which may be associated with the reaeration rate coefficient...
Turbulent Velocity and Gas Concentration Measurements in the Near-Surface Layer
An experiment was undertaken to study the mechanism of interfacial mass transfer. Near-surface liquid turbulence and oxygen concentration fluctuations have been measured in a grid-stirred...
Isotropic Fractionation During Air-Water Transfer of Oxygen and Nitrogen
We present empirical results that show the kinetic fractionation during gas exchange is 0.9972 ? .0002 for oxygen and 0.9987 ? .0001 for nitrogen. These values are larger than the solubility...
A Fluorescence Technique to Measure Concentration Gradients near an Interface
A new fluorescence technique which measures the concentration profile in a mass transfer boundary layer is described. It uses a tracer whose fluorescent intensity is inversely proportional...
Methane Tracer Technique for Gas Transfer at Hydraulic Structures
Using a simple headspace gas chromatographic technique, gas transfer at several hydraulic structures were investigated. Naturally occurring methane was used as a tracer gas to measure...
Dissolved Oxygen and Woody Debris: Detecting Sensitive Forest Streams
Early watershed studies showed that timber harvesting and yarding could depress dissolved oxygen in nearby streams when fresh slash entered streams and streamside shade was reduced. State...
Rainfall-Reaeration Effects
The effect of rainfall intensity on reaeration has not been adequately reported in the literature. It is clear that rainfall causes surface turbulence and increases reaeration, and a significant...
Epilimnetic Dissolved Oxygen Content and Surface Water Pump Performance
Surface water pumps have been operated and monitored at TVA's Douglas Dam since 1987. The purpose of these pumps is to improve the dissolved oxygen (DO) content of the hydropower...
Oxygen Transfer in Turbulent Shear Flows
Oxygen transfer equation for the air-water two-phase aeration region of turbulent shear flow in a vertical pipe is derived. Dimensionless variables significant in characterizing the transfer...
Technology Development for Auto-Venting Turbines
Experimentation with venting air into the hydroturbines at Norris Dam has convinced the Tennessee Valley Authority (TVA) that this is a viable method for increasing dissolved oxygen (DO)...
A Simple Empirical Model of Aeration at Navigation Dams
In a study of aeration at 28 dams in the upper Ohio River basin, site-specific least-squares linear regression models were used to describe the dissolved oxygen deficit below each dam...
Oxygen Transfer at Spillways
A relationship for oxygen transfer efficiency, E, at spillways and gated spillways with a hydraulic jump or plunge pool, has been developed from conceptual considerations and fit to measurements...
Oxygen Transfer in Full Lift Hypolimnetic Aeration Systems
A series of experiments were conducted to examine the effect of diffuser depth, diffuser orifice diameter and separator box surface area on oxygen transfer (mg/L), daily oxygen load (kg...
Sidestream Elevated Pool Aeration Station Design
The Metropolitan Water Reclamation District of Greater Chicago (MWRDGC) is constructing a system of five Sidestream Elevated Pool Aeration (SEPA) stations along the 35.8 mile Calumet River,...
Mechanical Aeration System Design for Reservoir Tailwater Enhancement
Low dissolved oxygen (DO) concentrations in tailraces below hydropower facilities has been identified as a problem at some projects during nongeneration periods. One technique which may...
Field Tests on a Bubbleless Membrane Aerator
A novel bubbleless hollow fiber membrane aerator has been developed and tested for the oxygenation of water. In this process pure oxygen is maintained on the inside of a bundle of sealed,...
Experiment on the Efficiency of an Aspirator-Blower Type Aerator
An aspirator-blower type aerator was designed and tested successfully for small lake application. The experiment showed that significant amount of air flow can be generated by the aspirator...
Theoretical Investigation of Oxygenating Bubble Plumes
Rehabilitation of lakes by oxygenation with air or oxygen plumes has been proven to be biologically feasible. Oxygenating plumes are released from areal sources and the gases are absorbed...
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