The sewage treatment of the third phase expansion of 6.5438+0.75 million t/d mainly accepts the domestic sewage of natural villages that have not been taken over in Mashan area and the production and domestic sewage of some newly introduced enterprises in the biomedical area of Mawei area. Membrane bioreactor (MBR) process is mainly adopted in the third phase of the project. Chlorine dioxide is used for disinfection of effluent, and belt concentration and filter pressing are used for sludge dehydration.