Comparative Study On The Characteristics Of The Microbial Growth About Different Sewage Treatment Process

To reveal microbial characteristics of Fluidized-pellet-bed(FPB)bioreactor,A~2/O process and DE Oxidation Ditch process,sludge in different heights(10cm,60cm and 120cm)of FPB,in different regions(aerobic,anoxic and anaerobic)of the A~2/O process and DE Oxidation Ditch process were sampled,through bacterial cultivation,the total bacteria counts,denitrifyimg bacteria counts and devulcanizating bacteria counts were detected.Meanwhile,the molecular biology method was also used to a comparative study on the microbial characteristics of the different sewage treatment process.The result demonstrates these:The result of bacterial cultivation shows that the total aerobic bacteria count per unit weight of sludge at 10cm in the FPB bioreactor was 2 times that in the aerobic region of the A~2/O process,and was 5 times that in the aerobic region of the DE Oxidation Ditch process.At 60cm and 120cm in the FPB,The denitrifying bacteria count was equivalent with that of the anoxic region of the A~2/O process and DE Oxidation Ditch process,but the devulcanizating bacteria count was between the anoxic and anaerobic region of A~2/O process and DE Oxidation process.The genomic DNA of microbial community was extracted directly through cells decomposition,and then amplified with the universal primers of Eubacteria and Archaebacteria(530F and 1490R).These amplified DNA fragments about 1kb were purified and then separated by denaturing gradient gel electrophoresis(DGGE),From that,DNA characteristic fingerprint spectrogram was obtained.PCR-DGGE fingerprint reveals,in the A~2/O process,there were 19 kinds of microorganisms at the aerobic region,18 kinds at the anoxic region and 15 kinds at the anaerobic region.;in the DE Oxidation Ditch process,there were 12 kinds of microorganisms at the aerobic region, 16 kinds at the anoxic region and 14kinds at the anaerobic region.;Compared with them, the microorganism communities of sludge in FPB bioreactor were very abundant,there are 23 kinds of dominant genera at the height of 10cm,21 kinds at 60cm and 20 kinds at 120cm.It means that the micro environment of the FPB bioreactor could be fitted for many kinds of microorganism growth and reproduction.The microorganism community structure and microorganism community succession result indicated:the comparability of the microbial communities in different regions(aerobic,anoxic and anaerobic)of the A~2/O process was 71.4.0%;the comparability of the microbial communities in different regions(aerobic,anoxic and anaerobic)of the DE Oxidation process was 75.0%;the comparability of the microorganism communities at the bottom,the middle and the upside of the FPB bioreactor is 83.1%.It indicated that the succession of microbial communities in the FPB bioreactor were not obvious and the community structure was relatively stable.Analysis of the the comparability of the microbial communities in FPB bioreactor, A~2/O process and DE Oxidation Ditch process using the UPGMA clustering algorithm, it showed that the similarity of the microbial communities in FPB bioreactor and A~2/O process was57.6%,the similarity of the microbial communities in FPB bioreactor and DE Oxidation Ditch process was45.3%.It means that the difference of micro environment was between the microbial communities in different heights of the reactor and in different regions(aerobic,anoxic and anaerobic)of the A~2/O process and DE Oxidation Ditch process.The identification of the special microbiology species in different sewage treatment processes waits on more researching.