Process for treatment of wastewater
AssigneeImperial Chemical Industries PLC
InventorDavid A. Hines
Life of this patent
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Abstract
A method and apparatus for treating wastewater by circulating it around a system comprising a downcomer and a riser communicating with each other at their lower ends, the level of the wastewater in the downcomer being above the level of the wastewater in the riser and providing a hydrostatic pressure head which causes circulation of the wastewater around the system, supplying a gas containing free oxygen to the wastewater as it passes through the downcomer, and pumping the wastewater up from, or from near, the top of the riser to a part of the downcomer, at or near the top thereof, which has, for at least a part of its length, a cross-sectional area which is less than the cross-sectional area of the remainder of the downcomer below the said part.
Claims6
Apparatus for the treatment of wastewater, comprising
- a riser having a wastewater level therein:
- a downcomer, having a wastewater level therein, communicating at its lower end with the riser, and having an upper part which has for at least part of its length a cross-sectional area which is less than the cross-sectional area of the rest of the downcomer below the upper part;
- means for providing a hydrostatic pressure head for effecting circulation of wastewater through the downcomer-riser system, said means including means for maintaining the level of wastewater in said downcomer in said downcomer upper part, and above the level of wastewater in said riser;
- means for supplying a gas containing free oxygen to the wastewater as it passes through the downcomer-riser system;
- and
- means for effecting rapid rectification of variations in the pressure head, said means comprising means for pumping wastewater up from an upper part of said riser to said lower cross-sectional area upper part of said downcomer.
Dependencies are inferred from the claim text.