The Research On Bio-electrode Process And Its Application In The Denitrification Of Wastewater

The bio-electro process combined the strongpoints of electro-chemical method and biology method. The complete and cleanly denitrification can be realized by this process. In this paper, the research findings and up-to-date research progress were introduced. The problems in the recent research were also summarized, and the developing trend of the technology were discussed in the end.Application of a bio-electrode reactor for treatment of nitrate polluted groundwater was investigated experimentally in this paper. The range of the optimum process condition was studied. When temperature was 35℃, the electric current was 100mA, the C/N concentration ratio was 1.07, and the hydraulic retention time(HRT) was 8 hour, a higher effect of nitrate removal ratio iwas achieved. For the treatment of nitrate polluted groundwater with different concentration, it had been found the bio-electrode reactor had a higher nitrate removal ratio more than 93% when the polluted water containing nitrate concentration less than 30mg/L at 8 hour of HRT and the C/N ratio of 1.07 was the most economical C/N ratio. At last, it was confirmed that a higher TN(total nitrogen)removal ratio more than 99% can be achieved to the nitrate polluted groundwater of Changsha region by experiment with groundwater.Application of a bio-electrochemical reactor for denitrification and neutralization treatment by direct feeding of an acidic wastewater containing copper ion and high-strength nitrate was investigated experimentally in this paper. Carbon electrodes were installed in the reactor as the anode and cathode, and denitrifying microorganisms were fixed on the surface of the cathode which were acclimatized to 100 mA of electric current and 5mg/L of Cu2+ subsequently. In order to find the characteristic of denitrification, a series of separate experiments were carried out at a constant HRT , but different with electric current , Cu2+ and C/N. It can be concluded that an effective removal of total nitrogen(TN) was achieved (TN removal was more than 90%) under the condition of T=35℃, 1=100mA, C/N=1.07, HRT=11h. The copper ions that remained in the reactor may have negative effect on denitrification, and it led to the appearance of lag time before denitrification strated and a decrease of maximum removal of TN. After some adaptation period, denitrification could proceed effectively regardless of the variation of copper ion concentration. The electric current that passed...