The Influence of MBR Aeration System on Microbial Activity and Water Quality

Membrane Bio-Reactor (MBR) is an efficient wastewater treatment technology that combines membrane separation technology and biological treatment technology. It has the advantages of high treatment efficiency, good effluent water quality, stable operation, and small land occupation. In the MBR process, the aeration system is the core part, which not only determines the activity of microorganisms but also directly affects the effluent water quality of MBR. Therefore, research and optimization of MBR aeration system are of great significance for improving the treatment effect of MBR.

One, the Influence of Aeration System on Microbial Activity

The microbial activity in MBR is a key factor determining the treatment effect of MBR. The MBR aeration system provides sufficient oxygen to provide momentum for the growth and metabolism of microorganisms. The size of the aeration amount directly affects the activity of microorganisms. Insufficient aeration will lead to insufficient dissolved oxygen concentration, reduce microbial activity, and lead to a decrease in treatment effect; while excessive aeration will lead to excessive dissolved oxygen concentration, causing microorganisms to be in an over-oxygenated state, which will also inhibit microbial activity, leading to a decrease in treatment effect. Therefore, reasonable selection of aeration amount is an important means to improve the treatment effect of MBR.

Two, the Influence of Aeration System on Water Quality

The aeration system in MBR not only affects the microbial activity but also directly affects the effluent water quality. The aeration system provides sufficient oxygen to fully oxidize and decompose the organic matter in the wastewater, and at the same time, through aeration, it can remove the suspended solids and particles in MBR sufficiently, thus improving the effluent water quality. However, the size of the aeration amount will also affect the effluent water quality. Excessive aeration will cause excessive removal of suspended solids and particles in MBR, resulting in high content of suspended solids and particles in the effluent, affecting the effluent water quality; while insufficient aeration, although it can reduce the content of suspended solids and particles in the effluent, it cannot fully exert the treatment effect of MBR, and the effluent water quality still cannot meet the requirements.

Three, Design and Optimization of MBR Aeration System

The design of MBR aeration system requires comprehensive consideration of the characteristics of MBR process and the requirements of wastewater treatment. During the design, it is necessary to fully consider the microbial activity and the requirements of effluent water quality in MBR, and reasonably select the aeration amount. In addition, the treatment effect of MBR can also be improved by adjusting the form and structure of the aeration system. For example, the use of microporous aeration blowers can improve the treatment efficiency of MBR and reduce energy consumption; multi-point aeration can improve the treatment effect of MBR and reduce energy consumption; variable frequency control can automatically adjust the aeration amount according to the operating status of MBR and the requirements of effluent water quality, improve the treatment effect of MBR, and reduce energy consumption.

In general, the impact of MBR aeration system on microbial activity and water quality is bidirectional, and it needs to be comprehensively considered in design and operation to achieve the best treatment effect of MBR.