| Summary: | 碩士 === 國立成功大學 === 環境工程與科學系 === 85 === This research was studied on evaluation technology of bioactivity applied in nitrification and denitrification processes, the evaluation technology is included of respirometer test, specific oxygen uptake rate(S.OUR), biochemical nitrogen potential(BNP test) and scanning electron microscopy (SEM). The purpose of this research was to make evaluation technology completely, and to investigate the mechanism and kinetics of substrate degradation in biological nitrification and denitrification processes. Automatic bubble respirometer was employed to measure nitrogen gas production in BNP test of denitrification instead of traditional measuring technique of gas production by manual method. The electrolytic repirometer also performed excellent accuracy and precision in measuring oxygen uptake of nitrification. Those two respirometers really provided efficient evaluation of bioactivity in biological nitrification and denitrification processes.
The biodegradation of ABS resin wastewater and acrylonitrile compound in denitrification was studied by BNP test using automatic bubble respirometer. The result of BNP test showed that the best COD/N ratio was 5 when ABS resin wastewater was utilized as the carbon source of denitrification. According to nitrogen gas production profile and COD utilization rate, in the total COD of ABS resin wastewater, 53% were easily biodegraded by denitrifying bacteria, 28% were hardly biodegraded by denitrifying bacteria and 19% could not be degraded in denitrification. The result of BNP test with acylonitrile substrate indicated that acrylonitrile showed a great inhibition to the denitrifying bacteria. The results of different compound utilization also showed that the carbon source which denitrifying bacteria used in denitrification was not acylonitrile but acrylic acid which was turned from acylonitrile before denitrification.
The biodegradation kinetic of ABS resin wastewater by denitrifying bacteria obeyed to Halden inhibition model. The critical concentration of ABS resin wastewater was 971 mg/L COD to the suspended denitrifying sludge and 1691 mg/L COD to the attahced denitrifying sludge present in an anoxic fluidized bed.
Performance evaluation of nitrification and denitrification in a full-scale SBR process in dicated that the SBR system could achieve high performance of COD and BOD removal, but the nitrification function was limited. The S.OUR and the BNP test of the existed sludge in SBR system showed poor bioactivity of nitrification and denitrification. Two suggestions were studied by the evaluation technology to improve nitrification and denitrification function of the SBR system. The aeration period should be extended and the nitrifying sludge should be reseeded in the SBR reactor.
A series of evaluation technology were approved to be the powerful measure to improve process performance of nitrification and denitrification in the batch biosystem as well as in the continuous biological process.
|
|---|
