Primary Research on the Disposal of Organic Wastewater of Low C/N Ratio with Electrode-Membrane Biological Reactor

The paper gave a brief introduction to electrode- membrane biological reactor (EMBR) and its denitrogenation mechanism. A experimental EMBR device was used to treat organic wastewater of low C/N ratio taken from septic tank. 9 groups of experiments were carried out to investigate the performance of the device with the variations of COD concentration and the C/N ratio of the influents as well as the electric current density of the reactor. According to the experiment results, the experimental EMBR had higher denitrogenation efficiency than traditional MBR owing to the cooperation of autotrophic and heterotrophic denitrification occurred in the anoxic chambers of the device. The change of electric current density and the C/N ratio of the influents had notable influence on denitrogenation process. On the conditions of the experiments, with the current density of 0.025 mA/cm², the experimental device had the highest nitrogen removal rate of 73.1 percents. The contribution of the heterotrophic denitrifying chamber and autotrophic denitrifying chamber to total nitrogen removal is respectively 57.8 percents and 42.1 percents. EMBR had the advantage of steady and high COD removal efficiency as traditional MBR did. The COD removal rate of the experimental device was above 97 percents.