ORBAL oxidation ditch-related type phosphorus and nitrogen removal integrated reverse A<2>O technology

Abstract

The present invention discloses an ORBAL oxidation ditch like inverted A2O process for integrally removing phosphorus and nitrogen,which comprises an outer ditch, a middle ditch, an inner ditch and a central island. Two settling ponds are jointly built at a first end or a second end of an inner wall of the outer ditch, and are tangential to or separated from an outer wall of the middle ditch. The areas among the inner wall of the outer ditch, the outer wall of the middle ditch, and the outer walls of two settling ponds are divided or divided by a partition wall, into a nitrified solution backflow region and a sludge backflow region. The outer ditch is designed to be an aerobic pond, the middle ditch is designed to be an anoxic pond, the inner ditch is designed to be an anaerobic pond, and the central island is configured to be an aerobic region which is connected with the outer ditch aerobic pond through a pipe. The sewage enters from a water inlet pipe to a sludge return flow region. The mixed sludge water in the sludge return flow region enters the middle ditch through wall holes of the middle ditch, orderly flows into the anaerobic pond of the inner ditch and the aerobic region of the central island, through wall holes of the ditch, and finally enters the aerobic pond of the outer ditch through a pipe. One branch of the water flow in the aerobic pond of the outer ditch flows into the anoxic region of the middle ditch through the wall holes after flowing into the nitrified solution backflow region through the wall holes, while the other branch is discharged after flowing into two settling ponds through the wall holes. The sludge in the two settling ponds enters the sludge return flow region through the wall holes. A part of sludge flows back to the aerobic region of the outer ditch, and the rest sludge is discharged. Each ditch chamber of the whole device is beautiful and rational in arrangement, easy to build, and ideal in flow.

Description

technical field [0001] The invention belongs to the technical field of sewage treatment, in particular to an ORBAL oxidation ditch-type integrated inversion of phosphorus and nitrogen removal designed by means of ORBAL or a joint-built ORBAL oxidation ditch. 2 O craft. Background technique [0002] On December 11, 2007, the applicant applied for the Chinese patent "ORBAL-like oxidation ditch-type integrated phosphorus and nitrogen removal A 2 O process", the sewage flows through the ORBAL oxidation ditch-like inner ditch / inner pool, middle ditch, and outer ditch in sequence. Oxygen pool or anaerobic pool, the outer ditch is designed as an aerobic pool, and the sewage flows through the inner ditch / anoxic pool in the inner pool, the anaerobic pool in the middle ditch, and the aerobic pool in the outer ditch. In the actual application process, considering the sewage in The residence time in the anaerobic pool, the anoxic pool, and the aerobic pool is respectively controlled t...

AI Technical Summary

Problems solved by technology

In the actual application process, considering that the residence time of sewage in the anaerobic pool, anoxic pool, and aerobic pool is controlled to be 1-2 hours, 0.5-3 hours, and 7 hours or more, the following problems are found during the design process: 1. , the central island is forced to be omitted, so that the sewage will not form a circulation in the inner ditch. Even if a central island partition wall is set in the middle of the inner ditch, due to the limitation of the residence time of the sewage, it can only be very narrow and long, and the circulation effect is very poor. Ideal; 2. The middle ditch is too narrow, and its width is generally less than 2 meters or even 1 meter, which is difficult to construct, especially after the propeller is placed in it, the circulation is difficult and it is difficult to achieve the best flow state. In addition, in order to achieve the appearance It is beautiful, and it is often necessary to cover the surface of the middle ditch to seal it, which increases investment; 3. When building with the secondary settling tank, the area between the inner wall of the outer ditch, the outer wall of the middle ditch, and the outer wall of the second settling tank is set as a separate area. In the nitrifying liquid return area and the sludge return area, in addition to the sewage feed pipe connected to the inner ditch, the anoxic tank in the inner ditch needs to be connected with the nitrifying liquid return area and the sludge return area, which also increases equipment investment

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