The third phase of the expansion of 17,500t/d wastewater treatment is mainly accepted by the natural villages in the Mashan area that have not yet taken over the sewage as well as the sewage of the newly-introduced enterprises in some of the bio-medical zones of Mawei area. The third phase of the project mainly adopts membrane bioreactor (MBR) process, the effluent is disinfected with chlorine dioxide, and the sludge is processed through belt thickening and filter press dewatering.