The Moving Bed Biofilm Reactor (MBBR) process requires suspended carriers with characteristics such as a specific gravity close to water, a high effective surface area, and suitability for microbial attachment and growth. Several domestic equipment manufacturers in China have successfully developed such carriers, and corresponding industry standards have been issued.

Under gentle agitation in the biochemical tank, the suspended carriers can easily float and move freely with the water, achieving an optimal fluidized state.

Under aerobic conditions, the buoyancy generated by aeration drives the movement of the carriers and surrounding water. As air flows through the water and the gaps between carriers, it is obstructed and broken into smaller bubbles. In this process, the carriers are thoroughly mixed with the water, while the airflow is finely dispersed, enhancing oxygen transfer efficiency and contact between the biofilm and oxygen.

Under anaerobic conditions, the water and carriers are fully fluidized by submersible mixers, ensuring sufficient contact between the biofilm and pollutants for effective degradation.

The core principle of the MBBR process is to achieve complete fluidization of the suspended carriers, thereby enhancing pollutant removal efficiency. In practical MBBR applications, key factors to consider include:

Biochemical tank design

Dosage of suspended carriers

Aeration system configuration

Retention screen design

Propeller/agitator selection