A novel CSTR-type of hollow fiber membrane biofilm reactor for consecutive nitrification and denitrification

摘要

A continuous stirred tank reactor(CSTR)type of hollow fiber membrane biofilm reactor(HF-MBfR)using composite membranes was investigated for the nitrogen removal in synthetic wastewater.The CSTR-type of HF-MBfR process couples autotrophic biological nitrogen removal reactors with the bubbleless mass transfer of oxygen and hydrogen through hollow fiber membranes.For nitrification,CSTR-type of HF-MBfR was operated over 400 days and for hydrogenotrophic denitrification,CSTR-type of HF-MBfR was operated over 300 days.The maximum steady-state NH_4~+-N removal rate achieved was 0.25 kg N/m3 day(2.06 g N/m2 day)and the denitrification rate achieved was 0.22 kg N/m3 day(1.72 g N/m2 day).Consequently,in the HF-MBfRs,biofilms were formed stably on surface of membranes,and nitrification and hydrogenotrophic denitrification were performed successfully during long-term operation.