NITROUS OXIDE PRODUCTION DURING NITROGEN REMOVAL FROM DOMESTIC WASTEWATER

摘要

In order to systematically investigate N2O production during nitrogen removal from domestic wastewater, complete nitrification-denitrification and short-cut nitrification-denitrification were achieved using fixed-time control and process control, respectively. The results showed that N2O was mainly produced in nitrification and the dissolved N2O at the end of nitrification was converted to N2 during denitrification. Moreover, whether using NO2--N or NO3--N as electron acceptor, the dissolved N2O was reduced to N2. In addition, single carbon source had no effect on the reduction of the dissolved N2O. N2O production during the complete nitrification was about two times higher than that during the short-cut nitrification. It was indicated that the type of nitrification strongly affected N2O production and N2O emission. It was possible that N2O production during nitrite oxidization caused higher N2O production during complete nitrification. In this experiment, short-cut nitrification-denitrification was achieved using process control without DO limitation. We therefore suggest that the way of achieving short-cut nitrification-denitrification used in this study can reduce and control N2O production from domestic wastewater treatment process.