MBBR packing is used as aerobic biological carrier in aerobic biological fluidized bed process. The packing is of hollow structure and normally operates. The packing is suspended in water. Anaerobic bacteria grow inside the packing to produce denitrification, which can remove nitrogen; aerobic bacteria grow outside to remove organic matter, and there are both nitrification and denitrification processes in the whole treatment process.

Because of the influence of flanging, the contact between the packing rings during packing changes from linear contact to point contact. In this way, the gap between the packing particles is increased and the resistance of the gas passing through the packing layer is reduced, and these contact points can also be the convergence and dispersion points of the liquid flowing along the packing surface, so as to promote the surface renewal of the liquid membrane and improve the mass transfer efficiency of the packing.