Process and device for treating sewage through denitrification and dephosphorization by oxic-anaerobic-anoxic-oxic (OAAO) plus membrane bioreactor (MBR) process

Abstract

The invention belongs to the field of sewage treatment, and discloses a process and a device for treating sewage through denitrification and dephosphorization by an oxic-anaerobic-anoxic-oxic (OAAO) plus membrane bioreactor (MBR) process. A pre-aerobic tank is arranged on the basis of the inverted anaerobic-anoxic-oxic (A<2> / O) process flow; and meanwhile, a membrane separation technology is used for substituting two sedimentation units of sedimentation tanks. According to the process, pre-treated sewage flows into the pre-aerobic tank, an anoxic tank and an anaerobic tank respectively; and the sewage flows into an MBR tank through the pre-aerobic tank, the anoxic tank, the anaerobic tank and an aerobic tank, is filtered by a membrane component and is drained. By the process for treating the sewage, a mixed liquor of the MBR tank can flow back to the pre-aerobic tank by arranging the pre-aerobic tank before an inverted A<2> / O process and changing influent and reflux modes, so that dissolved oxygen generated by the excess aeration of the MBR tank can be efficiently utilized; and the inverted A<2> / O process is adopted, so that the internal circulation caused by the denitrification and dephosphorization is avoided, the internal circulation volume of the mixed liquor is reduced, and the operation and maintenance cost which is required by the internal circulation is correspondingly reduced. The water quality of effluent treated by the method meets the requirements of I-class A criteria of Integrated Wastewater Discharge Standard (GB 8978-1996).

Description

technical field [0001] The invention belongs to the field of sewage treatment. Background technique [0002] The shortage of water resources and energy and the deterioration of water environment quality have increasingly become the bottleneck of social and economic development. It is imperative to increase the rate and degree of sewage treatment, strengthen the efficiency of nitrogen and phosphorus removal in sewage treatment plants, and reduce the energy consumption of sewage treatment. With the improvement of the effluent quality of sewage treatment plants, the existing sewage treatment plants generally have insufficient carbon sources. How to improve the efficient utilization of carbon sources in the existing sewage treatment process and reduce the concentration of pollutants in the effluent is a problem that needs to be solved urgently. [0003] Membrane bioreactor technology (MBR) is the product of the organic combination of membrane separation technology and sewage bi...

AI Technical Summary

Problems solved by technology

[0007] The present invention aims to solve the technical problems of effective utilization of carbon sources in the traditional activated sludge wastewater treatment process and the energy consumption of existing MBR membrane bioreactors. Nitrogen and phosphorus removal sewage treatment process and equipment

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