Study Of Fe^Ⅱ（EDTA）-NO Bio-Reduction And N₂O Control

BioDeNOx is a new technology for the flue gas treatment, it both has the advantages of chemical absorption and biological denitrification technology. BioDeNOx has the advantages of low investment, low cost, short process, simple operation, getting more and more attention. While in BioDeNOx, N2O is a main intermediate product. Some studies have shown that N2O can intensify the greenhouse effect, the destruction of the ozone layer and promote the formation of acid rain. Therefore, it is improtant to study the FeⅡ(EDTA)-NO biological nitrate reduction and the N2O emission control.1) The FeⅡ(EDTA)-NO has a certain toxicity to microbial, so we use a phased domestication way.The domesticated sludge has a good biological reduction characteristics of FeⅡ(EDTA)-NO, the maximum removal concentration is5mmol·L-1, the FeⅡ(EDTA)-NO removal rate was significantly reduced when make the concentration more than5mmol·L-1.2) Throgh the kinetics of biological reduction, we found the maximum reduction rate was o.77mmol·L-2·h-1compare with other carbon sourse. The optimum C/N was2.4when use glucose as carbon sourse. The best FeⅡ(EDTA)-NO biological reduction temperature was35℃.2) Comparing with other carbon sourse, the accumulation and conversion rate of N2O was lowest with glucose. The intermediate production of N2O ewas accumulated when the C/N lower then2.4; The solution pH decrease, the N2O accumulation and generation became higher. There was no N2O under under alkaline condition. The best temperature was35℃, the N2O accumulation and generation were lowest compared with other temperature. FeⅡEDTA can be used as electron donor, and the higher concentration, the lower N2O accumulation. But compared with the same concentration of glucose, the N2O was more conducive; The low concentration of SO32-had litter effect on the accumulation of N2O.3) The PCR-DGGE research showd that the main strains in the FeⅡ(EDTA)-NO biological reduction were:Geovibrio、Agrobacterium、 Enterobacter、Pantoea、Klebsiella、Pseudomonas. And the bacterium in this system were changed obviously under differernt influence factors.