1994 Volume 29 Issue 4 Pages 225-233
The emission rate of nitrous oxide (N2O) from the night soil treatment plants with the high loading nitrification-denitrification (or high rate aerobic biological treatment) process, which become more common in these years in Japan, was measured at two Facilities. The high concentration, 1400-3300 ppm, of N2O was observed in the aeration air in the reaction chamber, regardless nitrification or denitrification processl at one Facility, and the conversion rate of N2O from the nitrogen content of night soil and sludge of septic tank was preliminarily estimated to be about 20% of gaseous components emitted from the chamber. At another Facility, however, the conversion into N2O was less than 0.3%. These results indicate that the conversion into N2O can occur at high rate in some types of night soil treatment plant. The detailed analysis of the phenomena can be expected to elucidate the N2O formation mechanisms in nitrification-denitrification process.
