SUNWei.Optimization of Mixed Liquid Reflux System in Modified A2/O Membrane Bioreactor of Beihu Wastewater Treatment Plant[J].China Water & Wastewater,2022,38(10):70-73.
Optimization of Mixed Liquid Reflux System in Modified A2/O Membrane Bioreactor of Beihu Wastewater Treatment Plant
China Water & Wastewater[ISSN:1000-4062/CN:12-1073/TU]
volume:
第38卷
Number:
第10期
Page:
70-73
Column:
Date of publication:
2022-05-17
- Keywords:
- A2/O biological tank; membrane bioreactor; high concentration mixed liquid reflux; diversion/distribution plate; enhanced biological nitrogen and phosphorus removal
- Abstract:
- A combined process consisting of high concentration modified A2/O biological tank and MBR is applied for the treatment of 40×104 m3/d wastewater in Beihu wastewater treatment plant. In this project, an optimal design scheme of the mixed liquid reflux system, namely a modified A2/O biological tank mixed liquid diversion/distribution device, was proposed to make full use of its advantages of high sludge concentration, small footprint area, good effluent quality and high degree of automation, and eliminate the disadvantages of poor biological nitrogen and phosphorus removal caused by the limitation of bad mixed liquid reflux conditions. The device consisted of a diversion/distribution plate system, a mixed liquid introduction system and a mixed liquid discharge system. By vertical separation of the introduction and discharge points in the same plane position, two relatively independent spaces were formed, and the introduction and discharge of the mixed liquid between different zones were realized in different height spaces, so as to build an efficient mixed liquid reflux system. The solution is ingenious and simple, and can be widely used in various biological tanks with plug-flow structure, simultaneous nitrogen and phosphorus removal and multi-stage reflux requirements, such as UCT process, VIP process, A2/O and its various deformation processes. The device can save energy consumption and improve the effect of biological nitrogen and phosphorus removal. The energy consumption of mixed liquid reflux in Beihu wastewater treatment plant is 0.001 7 kW·h/m?，which saves 50%-85% energy. The average denitrification rate was 73%, and the highest denitrification rate was 93%.
Last Update:
2022-05-17