NITROUS-OXIDE EMISSIONS FROM WASTE-WATER

The estimation of nitrous oxide emissions is complicated by the high d egree of uncertainty on the emission factors involved and by the limit ed acquaintance with all significant nitrous oxide sources. A potentia lly important source for which emission data are lacking is the sewage system transporting waste water from human activities. For this study an experimental measurement campaign has been carried out on waste wa ter sampled at different sewage treatment plants. The nitrous oxide de veloping from the water samples was monitored by means of gas chromato graphy. The methodological analysis was based on the concentration/tim e curves obtained. Our results indicate that the formation of nitrous oxide from the waste water matrices results from microbiological denit rification. We deduced tentative emission factors for the wastewater t ypes studied.