Advanced purification process for secondary effluent from municipal wastewater treatment plant

Abstract

The invention discloses an advanced purification process for secondary effluent from a municipal wastewater treatment plant and aims at solving the problems of complex treatment process, high cost and the like in a conventional secondary effluent purification treatment process. The invention adopts the technical scheme that the advanced purification process comprises the following steps: a. carrying out biological reaction and algae liquid separation, wherein the biological reaction means that wastewater of the secondary effluent is fed into a photobioreactor for carrying out a photobiological reaction; algae-bacteria symbionts are inoculated into water in the photobioreactor, and the algae-bacteria symbionts consist of chlorella and activated sludge bacteria. The algae liquid separation means that reaction liquid finishing reaction in the photobioreactor is fed into an algae-bacteria separating chamber and preseparated by a gravity sedimentation method to obtain upper supernatant and lower algae liquid; the lower algae liquid undergoes centrifugal separation to obtain centrifugal supernatant and a centrifugal algae body, the upper supernatant and the centrifugal supernatant are naturally discharged. The advanced purification process disclosed by the invention has the advantages of simple process, short hydraulic retention time, good wastewater treatment effect, environment friendliness and additional economic benefits.

Description

technical field [0001] The invention relates to the field of sewage treatment, in particular to a deep purification process suitable for secondary effluent of urban sewage treatment plants. Background technique [0002] The existing sewage treatment technologies mainly include microbial method and membrane technology method. Among them, the traditional microbial method uses the growth of microorganisms to consume nutrients in sewage to reduce carbon sources and purify water. However, the carbon-to-nitrogen ratio must meet certain requirements during the growth of microorganisms. Therefore, when the carbon source in the sewage is exhausted by the microorganisms, the microorganisms will naturally stop working, and the continuous growth of the microorganisms cannot be guaranteed when the carbon source is reduced, which affects sewage treatment. Effect. At this time, the remaining nitrogen substances in the sewage are at least 20mg / L, which is much higher than the environmenta...

AI Technical Summary

Problems solved by technology

However, the one-time investment of membrane technology equipment is too high to be applied on a large scale and continuously

[0003] For the existing sewage treatment, there is only input but no output, and it cannot produce economic benefits, resulting in high costs. Among them, the traditional domestic sewage treatment technology not only has high operating costs, but the nitrogen and phosphorus content in the treated discharge water is still as high as 20mg / L. Can not meet the minimum requirements of GB3838-2002 "Surface Water Environmental Quality Standards" category V (mainly applicable to agricultural water areas and waters with general landscape requirements) environmental quality standards basic item standard total nitrogen limit

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