ORBAL oxidation ditch type similar dephosphorization denitrogenation integrated A2O technique

Abstract

The invention relates to an A<2>O technique with the integration of dephosphorization and denitrification and is similar to an ORBAL oxidation ditch, and pertains to the technical field of sewage treatment. Sewage flows through an inner ditch / inner tank, a middle ditch and an external ditch in sequence and all the ditches are similar to the ORBAL oxidation ditch; the inner ditch / inner tank is designed as an anaerobic tank or an anoxic tank; the middle ditch is designed as an anoxic tank or an anaerobic tank; the external ditch is designed as an aerobic tank. The technique combines the advantages of the ORBAL oxidation ditch, the A<2>O technique and a reversed A<2>O technique; compared with other common activated sludge methods, the invention can remove more phosphorus from the sewage, and has better dephosphorization and denitrification effect; the whole process has small area occupancy; integrated construction technique particularly can construct a secondary settling tank, reflux of nitrification and reflux of sludge in an integrate way; floor area is greatly saved by sharing walls, and investment capital for equipment is low.

Description

technical field [0001] The invention belongs to the technical field of sewage treatment, in particular to an ORBAL oxidation ditch-type integrated phosphorus and nitrogen removal designed with the help of ORBAL or a joint ORBAL oxidation ditch. 2 O / Invert A 2 O craft. Background technique [0002] A typical ORBAL oxidation ditch is composed of an outer ditch (anaerobic ditch), a middle ditch (anoxic ditch) and an inner ditch (aerobic ditch) in series. , High investment cost, in order to overcome the shortcomings of large floor area and high investment cost, Chinese patent CN200610038130. The secondary settling tank, the secondary settling tank is tangent to or shares the wall with the inner wall of the outer ditch. The typical ORBAL oxidation ditch has a good denitrification effect, but due to the long residence time (generally more than 16 hours), the phosphorus removal effect is not ideal. Anaerobic-aerobic process, the anoxic tank is in the outer ditch, the anaerobic ...

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Problems solved by technology

[0002] A typical ORBAL oxidation ditch is composed of an outer ditch (anaerobic ditch), a middle ditch (anoxic ditch) and an inner ditch (aerobic ditch) in series. , High investment cost, in order to overcome the shortcomings of large floor area and high investment cost, Chinese patent CN200610038130. The secondary settling tank, the secondary settling tank is tangent to or shares the wall with the inner wall of the outer ditch

The typical ORBAL oxidation ditch has a good denitrification effect, but due to the long residence time (generally more than 16 hours), the phosphorus removal effect is not ideal. Anaerobic-aerobic process, the anoxic tank is in the outer ditch, the anaerobic tank is in the middle ditch, and the aerobic tank is in the inner ditch. Compared with the typical ORBAL oxidation ditch, its denitrification and dephosphorization effects have been improved, but Like a typical ORBAL oxidation ditch, phosphorus removal is not ideal, because the outer ditch is long and the volume is large, the residence time of sewage in the anaerobic zone or anoxic zone is long, and the residence time in the aerobic zone of the inner ditch Short, it has little effect on the removal of BOD and COD, but in actual operation, the effect of nitrogen and phosphorus removal, especially phosphorus removal is not good

[0003] Typical A in sewage treatment 2 O craft or invert A 2 O process, the residence time is generally 7-14 hours, which has a good effect of nitrogen and phosphorus removal, but its volume is large and the investment cost is high

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