| In this thesis, MBR(Membrane Biological Reactor) technology and BER (Biofilm-electrode Reactor) technology were intergrated to produce a new kind of electrochemical-physicochemical-biochemical denitrogenation process, which is named EMBR(Electrode-Membrane Biological Reactor). Experiments were carried out to dispose the organic wastewater of low C/N ratio from the septic-tank in self-made EMBR experimental device. Technological propoties, biochemical characteristics, denitrifying mechAnism and the denitrification mathematic pattern of EMBR were systematically studied.The contents and the main achievements of this research include:(1) Denitrifying experiments were carried out with simulated wastewater of low C/N ratio in self-made activated carbon fiber electrode-biofilm experimental device. According to the experiment results, the experimental BER system could evidently strengthen the denitrification process with low C/N ratio and low consentration of the organics of the influents. As the C/N ratio was less than 3.0, the denitrifying efficiency increased with the enhance of the C/N ratio. With appropriate influent C/N ratio, organic concentration and working current density, the denitrification efficiency of the experimental BER could be 6 to 15 percents higher than that of simple biofilm reactor. With the invariable influent C/N ratio, the increase of the concentrations of the influent pollutants would accordingly lead to the increase of the optimum current density of the device, while the denitrification efficiency would decrease simultaneously.(2) Self-made activated carbon fiber electrodes were installed in a A/O-MBR to form a experimental EMBR system. An orthogonal experiment was conducted with septic wastewater of low C/N ratio to acquire the optimum working parameters of the experimental EMBR. The technological experiments were carried out to remove the pollutants from the influents afterwards. The experimental results showed that EMBR had similar characteristics of high removal efficiency to MBR. On the optimum technological conditions and with the influent COD concentration of 130mg/L and the C/N ratio of 3.0, the average removal efficiency of the turbidity, COD, NH4+-N and TN of the influents of the experimental EMBR were respectively 96.4%,93.1%,84.5% and 62.3%, and the average concentrations of the turbidity, COD, NH4-N and TN of the efflents were respectively 3.5NTU,8.8mg/L,4.2mg/L and 14.6mg/L, which could successfully meet the quality requirements of water reuse. The multiple denitrifying chamber played an important role in the denitrifying process, with the total nitrogen removal efficiency of 9.1%. The denitrification process in EMBR and MBR was contrasted and discussed by experiments. The TN removing effiency of EMBR was 7.3 % higher than that of MBR. Meanwhile, the experimental EMBR had the same ability of resisting the impact load of COD as MBR, whereras the impact of the NH4+-N loading would apparently decrease the denitrifying efficiency of device, and a interval of about 2 weeks would be necessary for the resume of the denitrifying function of EMBR.(3) In the internal of EMBR, electrochemical reaction was the premise of strengthened denitrification, and biochemical reaction was the necessary pathway for electrochemical reaction of denitrification. The interaction and the influence between electrochemical reaction and biochemical reaction existed to form specific biological-chemical coupling system to promote the denitrifying capability of the technology system. In the multiple denitrifying chamber of EMBR, the change of current density influenced degradation rate of TN significantly. With experimental water quality of the effluents and the operating parameters, the maximum degradation rate of TN occurred at the current density of 0.03 mA/cm2.When current density was excessive, "Hytrogen Inhibition" emerged analogously. With appropriate current density and higher activity of electrode-biofilms, the stronger the denitrifying capability and the hytrogen utilization of the microbes were, the faster the electrochemical reaction proceeded.(4) In technology system of EMBR, denitrification processes relyed on four kinds of biochemical reactions, which were known as amination, nitration, heterotrophic denitrification and autotrophic denitrification. Amination and nitration occurred mainly in aeration chamber. Heterotrophic denitrification played an important role in denitrogenation process and occurred mainly in the front heterotrophic denitrification chamber of the reactor. Heterotrophic-autotrophic mutiple denitrification took placed in the multiple denitrifying chamber of EMBR, which was the main characteristics of the process. Integrating the denitrification of electrode-biofilms and the suspended sludge, with the specific structure of the mutiple denitrifying chamber and the working conditions of EMBR, an empirical model of heterotrophic-autotrophic mutiple denitrification was constructed as follows:N= KN·lambertw(1/KN·exp(-MLSS·(9.12j+0.465)/KN·t-MLSS·(9.12j+0.465)/KN·Cl))...
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