Method for strengthening biological phosphorus removal of municipal sewage A/O process through internal reflux of sludge

Abstract

The invention discloses a method for strengthening biological phosphorus removal of municipal sewage A / O process through internal reflux of sludge, belongs to the field of advanced sewage treatment, and solves the problem that the phosphorus removal performance of a biological phosphorus removal system becomes poor easily due to conversion of phosphorus accumulation metabolism into glycan metabolism. The method comprises steps: firstly, adjusting the DO concentration ranges of an anaerobic section and an aerobic section to be 0-0.1 mg / L and 2-4 mg / L respectively, the SRT of a system to be 10-12 d, the HRT of the anaerobic section and the HRT of the aerobic section to be 2 h and 5 h respectively, and the MLSS range of the anaerobic section to be 2500-3500 mg / L; secondly, increasing internal reflux of sludge in the anaerobic section, namely refluxing 20% of sludge at the end of the anaerobic section to the beginning of the anaerobic section so as to improve the phosphorus load of the sludge in the aerobic section, and inducing glycan metabolism to be converted into polyphosphate metabolism by promoting excessive phosphorus absorption of the sludge in the aerobic section so as to strengthen the phosphorus removal performance of the system; and meanwhile, controlling SRT to be 10-12 d, and discharging phosphorus from the system in the form of phosphorus-rich sludge; returning the undischarged sludge to the initial stage of the anaerobic section, namely controlling the external reflux ratio of the sludge, stopping internal reflux of the sludge in the anaerobic section after the TP removal rate of the system is greater than 95% and maintaining for two weeks, and considering that the TP removal performance of the system is enhanced.

Description

technical field [0001] The invention belongs to the field of urban sewage treatment and regeneration. Specifically, by adding sludge internal reflux at the end of the anaerobic section of the A / O process flow, it promotes the utilization of organic carbon sources in raw water by phosphorus-accumulating bacteria, thereby realizing enhanced biological phosphorus removal. The rapid startup and performance recovery of biological phosphorus removal system provides a new idea. Background technique [0002] Phosphorus is an important biological nutrient and a limiting factor for the growth of surface freshwater organisms. Therefore, massive discharge of phosphate-rich urban sewage can lead to eutrophication of freshwater bodies. The excessive growth of algae and plankton consumes a large amount of dissolved oxygen in the water body, resulting in the death of aerobic organisms such as fish due to lack of oxygen. A large amount of organic matter accumulates and ferments under anaer...

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Problems solved by technology

However, the application of the above invention patents to the mainstream wastewater biological phosphorus removal process has the problems of high operating costs, large equipment footprint, and inconvenient operation and management.

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