Oxidation ditch sewage disposal method including rotational flow spreading treatment and device thereof

Abstract

The invention relates to an oxidation ditch sewage disposal method including rotational flow spreading treatment, wherein the method includes steps of disposing sewage in a grit basin, an oxidation ditch, and a secondary sedimentation tank; backflowing at least a part of mud in the secondary sedimentation tank to a water inlet of the oxidization ditch; performing the rotational flow spreading treatment on the mud returned to the water inlet from the secondary sedimentation tank through a rotational flow spreader; intensifying the hydraulic shearing effect of the periphery of the active sludge by a speed gradient field in the rotational flow yard, and guaranteeing the high activity of zoogloea surface, removing refractory mesh impurities cpated on the surface of a flocculating body and improving the mass transfer effect from the interface of the flocculating body to the center activity zone by combining with water; meanwhile, the method pushes the sludge flow of the base layer of the oxidization ditch, thus the sludge at the aeration zone is suspended in the water body, the sludge deposition is avoided, and the sludge utilization rate is improved. Through rotational flow, the aged sludge floated for gathering the grease and air bubble is broken during the biochemical process, thereby optimizing e eluent water quality, preventing sludge expansion and improving the settling performance. The invention further relates to a device for realizing the method.

Description

technical field [0001] The invention belongs to the field of sewage treatment process transformation, and relates to an oxidation ditch sewage treatment method and device including cyclone breaking treatment. Specifically, a cyclone breaker is added to the sludge return pipeline of the oxidation ditch system, relying on cyclone shear The shear force field and the centrifugal force field strengthen anaerobic / anoxic / aerobic microbial purification efficiency, and a device for realizing the method. Background technique [0002] Oxidation ditch is an activated sludge treatment system, which is different from the traditional activated sludge method in terms of hydraulic flow. Its aeration tank is a closed ditch type. etc. are concentrated in the oxidation ditch, which is in a push flow state in the short term and in a mixed state in the long term, and has a good ability to deal with organic matter that is not easy to degrade. The oxidation ditch process has become the preferred p...

AI Technical Summary

Problems solved by technology

[0003] At present, with the acceleration of urbanization, the composition of industrial and domestic sewage is more complex, including organic pollutants, oil pollutants, biological pollutants and toxic substances, which makes the traditional oxidation ditch process face greater difficulties in the operation process

The first problem is that when the carbohydrates in the wastewater are too high, the microbial load is too high, a large amount of highly viscous polysaccharides are accumulated, a large amount of water is attached to the sludge surface, and the sludge volume index (Sludge Volume Index, SVI ) value is very high, causing sludge bulking and filamentous bacteria growth

The second problem is that part of the grease or tiny air bubbles are enriched on the surface or pores of the sludge without being completely treated by the system, and circulated in the oxidation ditch and stirred with oxygen by rotating brushes to generate a large amount of foam, causing the sludge to become lighter and float up

Moreover, when denitrifying bacteria dissimilate nitrate, tiny nitrogen bubbles will be released, and the sludge will carry the bubbles up. If the bubbles are not discharged in time, the long-term circulation in the oxidation ditch will cause the sludge settling performance to decline, and ultimately affect the effluent water quality.

The third problem is that the oxidation ditch process mainly uses water flow to propel, and its circulation velocity is mainly determined by the influent flow velocity, return flow velocity, and aeration rate. ) too low will cause a large amount of mud accumulation at the bottom of the ditch, greatly reducing the effective volume of the oxidation ditch, reducing the mixing effect of microorganisms, oxygen and microorganisms, and affecting the water quality of the effluent, and strengthening the mixing and shearing effect in the tank by strengthening the aeration intensity It is bound to cause a waste of energy consumption for air aeration, and it will also produce a lot of foam

Chinese invention patent application 201310511102.5 proposes a synergistic oxidation ditch system with swirl aeration and plug flow nozzles, which uses swirl shear aeration to improve the oxygen supply effect to improve the oxidation ditch treatment efficiency, but does not solve some oil Or air bubbles are not completely treated by the system and are enriched on the surface of the sludge or in the pores, causing the sludge to float and expand.

To sum up, the above patents only propose solutions to certain problems in the oxidation ditch process, and upgrading the existing oxidation ditch system still faces problems such as high energy consumption, high cost and complex transformation.

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