MBBR is an aerobic biological carrier with hollow structure. During normal operation, the packing is suspended in water. Anaerobic bacteria grow inside the packing to produce denitrification, which can remove nitrogen, while aerobic bacteria grow outside to remove organic matter. There are both nitrification and denitrification processes in the whole treatment process.

MBBR provides a safe and comfortable environment for the mass reproduction of high-quality biological flora, and enhances its ability to degrade organic compounds in wastewater. Meanwhile, the abundant types of biological flora on the carrier enhance the degradation performance of refractory organic compounds and improve the effluent quality. At the same time, the biofilm sludge on the carrier has a long age, which makes the concentration of nitrifying bacteria increase, and the nitrification denitrification ability is significant.