Assessment of excess N2 and groundwater N2O emission factors of nitrate-contaminated aquifers in northern Germany

D. Weymann, R. Well, H. Flessa, C. von der Heide, M. Deurer, K. Meyer, C. Konrad, W. Walther
2008 Biogeosciences Discussions  
We investigated the dynamics of denitrification and nitrous oxide (N 2 O) accumulation in 4 nitrate (NO − 3 ) contaminated denitrifying sand and gravel aquifers of northern Germany (Fuhrberg, Sulingen, Thülsfelde and Göttingen) to quantify their potential N 2 O emission and to evaluate existing concepts of N 2 O emission factors. Excess N 2 -5 15 close to 0 and RP close to 1 but relatively high at a RP between 0.2 and 0.6. For the first time, we report groundwater N 2 O emission factors
more » ... ng of the ratio between N 2 O-N and initial NO − 3 -N concentrations (EF1). According to denitrification intensity, EF(1) was smaller than the ratio between N 2 O-N and actual NO − 3 -N concentrations EF(2). In general, these emission factors were highly variable within the aquifers. The 20 site medians ranged between 0.00043-0.00438 for EF(1) and 0.00092-0.01801 for EF(2), respectively. For the aquifers of Fuhrberg and Sulingen, we found EF (1) median values which are close to the 2006 IPCC default value of 0.0025. In contrast, we determined significant lower EFs for the aquifers of Thülsfelde and Göttingen. Abstract 5Abstract 20 Hannover. We thank I. Ostermeyer and A. Keitel for technical assistance.
doi:10.5194/bgd-5-1263-2008 fatcat:cof4wsdtdzazxk4pdyqcz4vy64