Active sludge floatation thickening device and method for membrane biological reaction tank process

Abstract

The invention relates to an active sludge floatation thickening device and method for a membrane biological reaction tank process. The device is provided with a flocculation reaction tank, a floatation tank and a water storage tank, wherein a blender, a sludge feeding port and a doser are arranged in the flocculation reaction tank; the floatation tank is provided with dissolved air release regions and floatation regions separated by half weirs, a sludge discharge trough and a sludge scraper, and a sludge collection pipeline is arranged at the bottom of the floatation tank; and the water storage tank is connected to the back side of the floatation tank, and is provided with a level regulator and a quick air-dissolving device. The method comprises the following steps: 1, controlling the discharge amount of surplus sludge; 2, adding a flocculant; 3, mixing the flocculated sludge with the air-dissolved water to form adhesions; 4, regulating surface solid loads in the floatation regions; 5, discharging clear solutions in the floatation regions; and 6, discharging the sludge. The invention is applicable to activated sludge thickening treatment in the membrane biological reaction tank process, and has the advantages of simple structure, reasonable design, convenient operation process and favorable effect.

Description

technical field [0001] The invention belongs to a sewage treatment technology, in particular to a method for concentrating excess activated sludge produced in the sewage biological treatment process, in particular to a high-efficiency method for the excess activated sludge produced in the sewage treatment process of membrane bioreactor tanks. An air flotation concentration device and a concentration method. Background technique [0002] At present, the membrane bioreactor is a new type of water treatment technology that combines a membrane separation unit and a biological treatment unit. The membrane module is used to replace the secondary sedimentation tank to maintain a high active sludge concentration in the bioreactor to reduce the cost of sewage treatment facilities. occupy less land and reduce sludge volumes by keeping sludge loads low. Specifically, it is to use the membrane separation equipment immersed in the biological tank to intercept the activated sludge and ma...

AI Technical Summary

Problems solved by technology

However, the dissolved air flotation method currently being used in the world still has some shortcomings and deficiencies, which are summarized as follows: (1) the process is complicated, there are many equipments, many operating points, the workload is heavy during the commissioning period, and the operation is highly dependent on automatic control; (2) ) High suspended solids in drainage, poor water quality, not up to the first-class B standard stipulated in my country's "Pollutant Discharge Standards for Urban Sewage Treatment Plants" (GB18918-2002); (3) Large drug consumption, various types, and high drug costs ; (4) The interlocking automatic control system of the liquid level of the air flotation tank and the drainage electric valve has a high failure rate and is unstable; and the study found that compared with the traditional activated sludge, the activated sludge particles produced by the membrane bioreactor process are smaller, and the specific gravity is the same as that of the traditional activated sludge. Similar to water, high organic matter content, difficult to settle and easy to float, it is difficult to treat with common concentration process, which is a recognized problem in the industry

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