The Study On Municipal Wastewater Treatment By Membrane Aeration Biofilm Reactor (MABR)

Biologic treatment technology keeps progressing since it was used 100 years ago. Membrane bio-reactors (MBRs) are new technology which combine the membrane technology and bio-reactor and developed rapidly in recent years. Membrane aeration biologic reactor (MABR) belongs to the Membrane bio-reactors.The treatment of municipal wastewater by a membrane aeration biologic reactor (MABR) made of coal-based carbon tube membrane was studied in laboratory scale in this study. The carbon membrane acts as biofilm carrier and bubbleless aeration device at the same time. Its special character of transmission lies in that ammoniate, organic carbon and oxygen supplied from opposite side of membrane penetrate into biofilm. This character makes MABR can achieve synchronous nitrification and denitrification.The experiment carried out for 430 days to study nitrification, denitrification and simultaneous organic carbon removal performance of carbon membrane MABR. And the impact to system for different dissolved oxygen (DO) concentration was studied, ratio of organic carbon to nitrogen (C/N), influent concentration, hydraulic retention time (HRT), aeration press and concussion loading rates was made and achieve some good results.Study suggests that the condition of dissolved oxygen 0.8 mg-L"1, hydraulic retention time 8 h and ratio of organic carbon to nitrogen 4～5 can be consider as the best parameter of the bio-reactor system. And in this operating condition, the removal efficiency of NH3-N, TN and COD were 95.34%, 83.50%and 72.82% respectively. The removal efficiency of NH₃-N was enhanced with DO rising and the efficiency could achieve 99.8%. But it did less effects when DO was more than 1.6 mg-L^-1. The ratio of organic carbon to nitrogen (C/N) does effect on denitrification and substance transmission of biofilm. A low ratio will result in lack of carbon resource for denitrification and a high ratio will result in difficulty of material transmission for biofilm excess increased. The system is steady when loading rates is high and it has a good capacity for shock loading rates. It keeps more than 90% of former efficiency when loading rates is doubled for 0.5 HRT and recovered completely after 1 HRT. The removal loading rates can be 0.258 kg NH3-N m^-3 d^-1, 0.920 kg COD m^-3 d^-1. In conclusion, this membrane aeration biologic reactor (MABR) made of coal-based carbon tube membrane has excellent capacity in nitrogen removal of synchronous nitrification and...