Studies the Factors of the Simultaneous Removal of Nitrogen and Carbon on Membrane Aeration Bioreactor

Abstract

A Membrane aerated bioreactor (MABR) capable of simultaneous nitrification and denitrification in a single reactor vessel was developed to investigate the factors of the simultaneous removal of nitrogen and carbon. The results showed that when the bubble point pressure of membrane modules is 25kPa, the relationship between oxygenation efficiency and intransmembrane pressure were not positively correlated, controlling the transmembrane pressure was 15kPa, oxygen supply rate (OSR) was the highest. During the earlier stage of operation, reducing the hydraulic retention time of MABR could improve the integral removal efficiency, when the HRT was 2h, the removal of COD and ammonia - nitrogen were respectively 70.29% and 52.3%. The dissolved oxygen in the reactor had a significant influence, with the dissolved oxygen （DO） concentration about 0.5mg/L, ammonia-nitrogen and total nitrogen removal efficiency was better, the removal rate were 79.5% and 63% respectively. The reaction tank had CO2 accumulation, and caused pH reduced to 5.8, the operation should maintain the pH at 7.5 by increasing the alkalinity of the raw water.