The Use of Pure Oxygen in
River and Impoundment Aeration
R. E. SPEECE, Professor
School of Civil Engineering
New Mexico State University
La Cruces, New Mexico
INTRODUCTION
In many present situations, the use of pure oxygen offers an economically
competitive alternative for artificial aeration of rivers and impoundments. Artificial
aeration presently is practiced to a limited extent and holds considerable potential
for the future. The author does not propose artificial aeration as a substitute for
adequate secondary treatment of wastewaters. However, there are common situations
where secondary treatment is not adequate to reduce the oxygen demand of wastewaters to the assimilation capacity of the receiving water without violating the DO
standards set for the river.
On the assumption that the tax dollar is limited, artificial aeration can be utilized
to maintain DO standards in many cases, at a far lower cost than low flow augmentation and various means of tertiary treatment. Hazen (1) has estimated that artificial
aeration would cost $33/1000 lb of oxygen transferred, using surface aerators. Davis
(2) made an economic analysis of water in the Potomac River and concluded "the
cost  advantage  of reaeration  devices over the alternatives is surprisingly large."
Destratification is most commonly attempted to restore DO and thus water
quality in stratified impoundments. However, in-place hypolimnion aeration has
definite engineering merit when compared to destratification. Pure oxygen injection
offers a sound approach to this means of maintaining good water quality in the
hypolimnion without destratifying the impoundment.
PURE OXYGEN
The use of pure oxygen minimizes capital investment since no compressors are
required. However, it increases operating cost. Davis (2) indicates this principle is
sound economically for artificial aeration installations.
River reaeration, utilizing pure oxygen, dates back at least to 1953 (3), when it
was sparged into a paper mill effluent at Macon, Georgia, with about 14 per cent
absorption efficiency. Also, pure oxygen has been injected into the pressure side of
a power turbine at Willamette Falls, Oregon (4), achieving 40 per cent absorption.
Another case (5) involves a pumping system which withdraws a portion of the
stream flow at a paper mill in Louisiana and forces it through an oxygen absorption
chamber operated at a pressure of 68 psig.   The oxygen supersaturated water is re-
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