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US 4,797,212 AGranted
Biological purification of waste waters
OwnerReinhart von Nordenskjoldinventor
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OwnerReinhart von Nordenskjoldinventor
Estimating the term…
In the particular embodiments of the waste water treatment system described in the specification, a waste water treatment basin has spaced-apart, moving aerator chains extending across the basin in a direction transverse to the flow of waste water through the basin. When an aerator chain is provided with air, bottom aerators suspended from the chain adjacent to the bottom of the basin move with respect to the basin to mix sludge collected on the basin with the waste water and to supply air to the waste water. A control system supplies air selectively to the aerator chains to provide zones of full aeration and intermediate zones with little or no aeration and the selection of the aerator chains is changed periodically in a progressive manner along the basin so that the zones move progressively through the basin. As a result, sufficient air is supplied to the waste water in the basin for purification of the waste water and to maintain sludge in suspension as required in the waste water at minimum expense of energy. In addition, the oxygen potential of the waste water in the zones is controlled so that successive reactions relating to the purification process are accomplished in successive zones, for example, including nitrification of the waste water in zones having a relatively high oxygen potential and denitrification in adjacent zones having relatively low oxygen potential. Phosphorus removal is accomplished in a similar manner.
A process for the biological purification of water in a basin having a plurality of aerator chains installed in generally parallel spaced-apart relation across the basin, the aerator chains each including a plurality of bottom aerators located close to the basin floor, the aerator chains being supported so as to move in a reciprocating way during operation so that the bottom aerators periodically move over the basin floor to mix sludge with the water, comprising supplying air sufficient for aeration and mixing of the sludge and waste water in the adjacent portion of the basin to one or more selected aerator chains while supplying less or no air to other aerator chains so that mixing of water and sludge takes place in the portions of the basin adjacent to the selected aerator chains, and periodically changing the selected aerator chains in a progressive manner through the basin to provide one or more zones which move through the basin in wave-like fashion in which mixing of sludge and water occurs.
A water treatment facility comprising a basin through which water flows in one direction during treatment, a plurality of aerator chains extending in generally parallel spaced-apart relation across the basin, a plurality of bottom aerators included in each aerator chain at locations adjacent to the bottom of the basin, the bottom aerators and the aerator chains being arranged to move with respect to the bottom of the basin when the aerator chain is fully aerated to mix sludge with the water and supply air to the water, air supply means, and control means for controlling the supply of air from the air supply means to each of the aerator chains selectively and causing spaced aerator chains in the plurality to be fully aerated and at least one aerator chain between the spaced chains to receive less or no air and for periodically changing the aerator chains which are fully aerated in a progressive manner along the length of the basin to produce aerated zones which move in a wave-like fashion through the basin.
Dependencies are inferred from the claim text.