Application And Characterization Of Physiology And Ecology Of Compound Nitrifying Bacteria

Six strains of autotrophic nitrifiers and 2 strains of heterotrophic nitrifiers were screened in the bio-ceramic reactor, and the physiology and ecology characteristic of nitrifiers were studied. The SBR was used to investigate the bioaugmentation effect of the nitrifiers and denatured gradient gel electrophoresis (DGGE) was also used for mutli-organism species analysis.The effect of organic carbon on the nitrification was discussed. The results showed that as the organic concentration of influent gradually decreased, the efficency of ammonia nitrogen escalated, ammonia nitrogen concentration of the effluent decresed.The average ammonia nitrogen removal rate was 43.57% at 1~7day, whereas average ammonia nitrogen removal rate was gradually increased to 64.38% at 15~21day. Correspondingly, the average nitrate concentration of effluent was 19.53 mg/L at 1~7day,whereas the average nitrate concentration of effluent was 30.52 mg/L at 15~21day. The nitrite concentration of effluent was in a low level and the maxiuma value was no more than 2.14mg/L.It was found that as organic carbon decreased, nitrifiers dominated over heterotroph in their competition. At the same time, a mass of heterotroph, those of which had weak adaptability or heavy dependence on organic carbon source, were eliminated. Microorganism varieties decreased dramatically in the process of evolvement of bacterial community structure. There were co-genus and also relatively specific germ genus in different operation periods of bio-ceramic reactor. All germ genus in bio-ceramic reactor constructed a ecological community frame.DGGE sequence analysis indicated that the dominant microorganism besides autotrophic bacteria,heterotrophic bacteria also survived in bio-ceramic reactor at the 21th day. Autotrophic bacteria contained Nitrosospira.sp and Nitrobacter sp., while heterotroph contained Bacillus sp., Pseudomonas sp. and Pseudochrobactrum sp.Nitrification rates of the strain YH1, YH2, YH3, XH1, XH2 and XH3 were 1.2mg/(L·d),1.2mg/(L·d), 1.2mg/(L·d), 1.25mg/(L·d), 1.06mg/(L·d), 1.13mg/(L·d),...