摘要 |
Oxygen containing gas is dissolved in sewage passing to, or through, a sewer during periods when sewage is being pumped therethrough. A stream of the sewage is withdrawn during periods when sewage is being held in the sewer. This stream is passed through a conduit so as to promote in such a stream dissolution of oxygen-containing gas introduced into, or entrained in, the stream. The stream is then returned to the sewer. By this means a chosen concentration of dissolved oxygen may be maintained in the volume of sewage between the points of withdrawal and return of the stream.
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