Study On Selection And Amplification Of Nitrifying Bacteria Culture Technology

There are some unexpected accidents, such as the death oflarge number of bacteria, toxic and hazardous substance spills resultingin sewage treatment nitrification function collapse during the operationof municipal sewage treatment plant. With long generation time, slowgrowth, sensitive to the change of environment, and so on, therecovery of nitrification cost a long time. When the nitrification ofwastewater treatment plant collapse, it not only cause the economiclosses for the discharge water under the quality but also harm to theenvironment and human.The primary goal of this study was to build a small volumebypass systerm outside the main process of wastewater treatment plantto enrich the nitrifying bacteria. This bypass systerm is independent ofthe main process, applying to the restart of the wasterwater treatmentplant main process adjustment and the remedy of nitrification collapseto shorten the time. This study mainly includes the following four parts:Study on the nitrifying bacteria enrichment technology in thesludge. In this pater nitrifying bacteria was enriched at the certaincondition in the MBR reactor using the pure inorganic and highconcentration ammomia water. The results showed that the nitrificationactivity (OUR) reached about250NH4+-N/L·h,50times that of theordinary sluddge after a period of160days of continuous enrichmentculture. Also the effluent concentration of NH4+, NO2-and NO3-werevery low. Study on the nitrifying bacteria retention. Compared theretention effect of the common sludge and the enriched sludge withhigh activity, we found that the enriched activity sludge was morefacifitable to retention. For the normal nitrifying sludge contained moreheterotrophic bacteria, nitrifying bacteria are strictly aerobic bacteria,even the oxygen was often given in the preservation process, the nitrification activity become very low after three weeks. On the contrary,in the enriched sludge, the nitrifying bacteria were relatively pure, thepreservation effect is relatively much betterat4℃and roomtemperature, the activity retention rate was87%,80%after threemonths preservation respectively. The preservation effect of4℃coldstorage was slightly better than that of room temperature.Isolation and purifying of nitrifying bacteria. Multiple strains ofdifferent colony morphology nitrifying bacteria were separated fromthe MBR reactor, confirming the nitrifying bacteria in MBR reactor was amixture of bacteria, containing a variety of nitrifying bacteria. Efficientnitrifying bacteria fermentation technology showed that by controllingthe reaction conditions, the nitrifying bacteria could be massproducted. Time as the abscissa, the logarithm of the number ofnitrifying bacteria, denitr as vertical axis, nitrifying bacteria growth curvecould be made.The quantitative PCR detection of nitrifying bacteria. Traditionaldenitrifying bacteria count method is time-consuming. In order toquickly detect the number of nitrifying bacteria, a quantitative PCRassay for detection of nitrifying bacteria was built which could quicklyand accurately detecte the number of nitrifying bacteria.