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

Abstract

The invention belongs to the technical field of the treatment of municipal sewage, and discloses a process and a device for treating sewage through denitrification and dephosphorization by an anaerobic-anoxic-oxic-anoxic (AAOA) plus membrane bioreactor (MBR) process. A rear anoxic tank is arranged on the basis of the traditional anaerobic-anoxic-oxic (A<2>/O) process flow; meanwhile, a membrane separation technology is used for substituting two sedimentation units of sedimentation tanks; according to the process, pre-treated sewage flows into an anaerobic tank, an anoxic tank and the rear anoxic tank respectively; and the sewage flows into an MBR tank through the anaerobic tank, the anoxic tank, an aerobic tank and the rear anoxic tank, is filtered by an MBR membrane component and is drained. By the process for treating the sewage, a carbon source in the sewage can be efficiently utilized by arranging the rear anoxic tank and changing influent and reflux modes, so that the denitrification and dephosphorization efficiency of the sewage is improved; and meanwhile, the membrane separation technology is used for increasing the concentration of activated sludge in the process for treating the sewage so as to realize the high-efficiency separation of mud and water in the sewage, so that the problems that the conventional process for treating the sewage is high in energy consumption, the floor area is large, and pollutants such as nitrogen, phosphorus and the like cannot be efficiently removed are solved. 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 technical field of urban 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] Among many nitrogen and phosphorus removal processes, anaerobic-anoxic-aerobic (A 2 / O) process is favored by...

AI Technical Summary

Problems solved by technology

However, due to the high gas-water ratio of the MBR membrane tank, the dissolved oxygen concentration of the mixed solution is as high as 5.0mg/L~10.0mg/L. If it is not used scientifically, not only the energy co

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