Konferenzpaper

Jahr der Veröffentlichung: 1998

Seiten: 59-73

Zeitschrift: Agribiological research : Zeitschrift für Agrarbiologie - Agrikulturchemie - Ökologie

Bandnummer: 51

Heftnummer: 1

ISSN: 0938-0337

Konferenz: Sessions on Sources and Sinks at the VDLUFA Congress

Verlag: VDLUFA-Verl.

Abstract: 

About 0.4-0.5 Tg nitrogen (1 Tg = 10(9) kg) are annually channeled through German waste water treatment plants. To quantify the gaseous N2O losses during the conversion of the above nitrogen inputs in situ measurements were carried out in the activated sludge, the nitrification-denitrification unit and the outflow of the waste water treatment plant of Giessen, Germany, during 1993-1996. Self-constructed floating PVC chambers were used to collect N2O. The gas was sucked and trapped on molecular sieve traps and quantified in the laboratory by gaschromatography (ECD). Until 1994 the municipal waste water of Giessen was purified only by an activated sludge unit. From 1994-1996 the waste water of meanwhile 150.000 inhabitants was splitted and purified partly by the activated sludge and partly by newly installed nitrification-denitrification units. Since 1996 the waste water is purified completely by nitrification-denitrification. In addition to N2O emissions, NH4+-N, NO3--N, NO2--N, BOD5, water temperature, pO(2) pH and the N2O dissolved in the waste water were determined. The dissolved N2O was quantified gaschromatographically after heating the samples for 80 min at 80 degrees C.

Generally speaking all compartments of the waste water treatment plant, Giessen, emitted annually about 188 kg N2O-N which corresponds roughly to about 0.02 % of the N input. During the winter period 1995-1996 an additional amount of 1005 kg N2O-N was discharged as dissolved N2O into the receiving river Lahn. These considerable amounts of N2O leaving a waste water treatment plant in dissolved form should not be overlooked in nitrogen balances. Second, the well and homogeneously aerated nitrification tank released about 45 times more N2O than the denitrification or 94 times more than the activated sludge unit. This surprising result should be considered if waste water treatment plants are extended more and more by nitrification-denitrifcation units. Finally, the contributions of waste water treatment plants to the overall German N2O budget seems to be relatively small so far. Because this very effective and relatively stable greenhouse gas N2O may increase in modern waste water treatment plants, the release of this trace gas should not be underestimated as potential global hazard on a longterm scale.

Harvard-Zitierstil: Sommer, J., Ciplak, G., Linn, A., Sumer, E., Benckiser, G. and Ottow, J. (1998) Quantification of emitted and retained N₂O in a municipal waste water treatment plant with activated sludge and nitrifying-denitrifying units, Agribiological research : Zeitschrift für Agrarbiologie - Agrikulturchemie - Ökologie, 51(1), pp. 59-73

APA-Zitierstil: Sommer, J., Ciplak, G., Linn, A., Sumer, E., Benckiser, G., & Ottow, J. (1998). Quantification of emitted and retained N₂O in a municipal waste water treatment plant with activated sludge and nitrifying-denitrifying units. Agribiological research : Zeitschrift für Agrarbiologie - Agrikulturchemie - Ökologie. 51(1), 59-73.