Modelling nitrogen transformations in the lower Seine river and estuary (France): impact of wastewater release on oxygenation and N2O emission
- 381 Downloads
A model of the ecological functioning of a drainage network (RIVERSTRAHLER: Billen, G., J. Garnier & Ph. Hanset, 1994. Modelling phytoplankton development in whole drainage networks: the RIVERSTRAHLER model applied to the Seine river system. Hydrobiologia, 289:119–137; Garnier, J., G. Billen & M. Coste, 1995. Seasonal succession of diatoms and Chlorophyceae in the drainage network of the river Seine: Observations and modelling. Limnology and Oceanography. 40: 750–765), has been developed to describe nutrient (N, P, Si) transfer processes at the scale of the whole Seine Basin taking into account human activities such as agricultural practices, waterscape and urban wastewater management. Whereas the upstream basin is strongly influenced by intensive agriculture, leading to high nitrate concentrations, the lower Seine River and estuary are densely populated. Paris and its suburbs represent alone up to 60% of the population in the basin (10.106 inhabitants), causing large amounts of ammonium to be released by domestic effluents discharged downstream from Paris (of which the Achères wastewater treatment plant –WWTP- treated up to 80%). The ammonium loading is completely nitrified in the upstream fluvial estuary (300 km farther the effluent outlet), which leads to a strong oxygen deficit in summer. A conceptual representation of nitrification was constructed in which microbial compartments were taken explicitly into account, and the intermediate production of N2O included. On this basis a physiological analysis of the two stages of the nitrification by nitrifying bacteria (ammonium and nitrite oxidizing bacteria) was carried out, as a function of the controlling factors (O2, NH 4 + , NO 2 − ; Brion, N. & G. Billen, 1998. Une réévaluation de la méthode d'incorporation de 14HCO3 pour mesurer la nitrification autotrophe et son application pour estimer les biomasses de bactéries nitrifiantes. Revue des Sciences de l'Eau, 11: 283–302; Cébron, A., J. Garnier & G. Billen 2005. Nitrous oxide production and nitrification kinetics by bacteria communities naturally present in river water (the lower Seine, France). Aquatic Microbial Ecolology, 41: 25–38). A mathematical formulation of the kinetics and the parameters values were incorporated into the general model of ecological functioning of the fluvial sector and freshwater estuary of the Seine River. N2O emissions due to denitrification were also considered. Results from summer field studies between 1998 and 2003 were used to validate the model which is able to reproduce the main spatial and temporal patterns of the activities of the microbial nitrifying communities as well as the levels of oxygen and nitrogen forms (NH 4 + , NO 2 − , NO 3 − N2O). Once validated, the model is used to examine the planned installation of a tertiary treatment at the Achères WWTP, scheduled for 2007 (a 90% reduction by nitrification of the presently discharged ammonium, and a 30% reduction of the nitrate by denitrification). The model shows that a nitrification treatment leads to a significant improvement in the oxygenation and a reduction of N2O emission. However, only further denitrification of urban effluents, expected in 2015, would significantly reduce the nitrogen delivery to the coastal zone.
KeywordsHuman impact Modeling Nitrogen transformations Seine river Wastewater treatment scenarios
This work was undertaken within the framework of the programmes Seine-Aval, funded by the Région Haute-Normandie and the Agence de l’Eau Seine-Normandie (AESN), and the PIREN-Seine funded by the CNRS and several institutions involved in the water management of the Seine River, including AESN and the Syndicat Interdépartemental pour l’Assainissement de l’Agglomération Parisienne (SIAAP).
- Berner, R. A., 1980. Early diagenesis. A theoretical approach. Princeton University Press, 256 pp.Google Scholar
- Billen, G. & P. Servais, 1989. Modélisation des processus de dégradation de la matière organique en milieu aquatique. In Bianchi, M. et al. (ed.), Microorganisms dans les écosystèmes océaniques, Chap. 8. Masson, Paris, 219–245.Google Scholar
- Billen, G., 1991. Protein degradation in Aquatic Environments. In Chrost, R. (ed.), Microbial Enzyme in Aquatic Environments. Springer Verlag, Berlin, 123–143.Google Scholar
- Billen, G., J. Garnier, N. Brion & N. Sanchez, 1998. Les transformations bactériennes de l’azote. Chapitre 13. In Meybeck, M., G. De Marsily & F. Fustec (eds), La Seine en son bassin. Fonctionnement écologique d’un système fluvial anthropisé. Elsevier, Paris, 567–592.Google Scholar
- Bouwman, A. F., J. M. Boumans & N. H. Batjes, 2002. Emissions of N2O and NO from fertilied fields: Summary of available measurement data. Global Biogeochemical Cycles, 16(4), 6/1–6/12.Google Scholar
- Brion, N. & G. Billen, 1998. Une réévaluation de la méthode d’incorporation de 14HCO3 pour mesurer la nitrification autotrophe et son application pour estimer les biomasses de bactéries nitrifiantes. Revue des Sciences de l’Eau 11: 283–302.Google Scholar
- Cébron, A., J. Garnier & G. Billen 2005. Nitrous oxide production and nitrification kinetics by bacteria communities naturally present in river water (the lower Seine, France). Aquatic Microbial Ecolology 41: 25–38.Google Scholar
- Garcia-Ruiz, R., S. N. Pattinson & B. A. Whitton, 1998. Kinetic parameters of denitrification in a river continuum. Applied & Environmental Microbiology 64: 2533–2538.Google Scholar
- Garnier, J., G. Billen & P. Servais, 1992. Physiological characteristics and ecological role of small and large bacteria in a polluted river (Seine River, France). Archiv für Hydrobiologie Beiheft Ergebnisse der Limnologie 37: 83–94.Google Scholar
- Garnier, J., G., Billen, Ph. Hanset, P. Testard & M. Coste, 1998. Développement algal et eutrophisation. Chapitre 14. In Meybeck, M., G. De Marsily & F. Fustec (eds), La Seine en son bassin Fonctionnement écologique d’un système fluvial anthropisé. Elsevier, Paris, 593–626.Google Scholar
- Garnier, J. & G. Billen, 2002. The Riverstrahler modelling approach applied to a tropical case study (The Red–Hong-River, Vietnam): nutrient transfer and impact on the Coastal Zone. SCOPE, Collection of Marine Research Works 12: 51–65.Google Scholar
- Garnier, J., G. Billen & Ph. Cugier, 2004. Drainage basin use and nutrient supply by rivers to the coastal zone. A modelling approach to the Seine River. In Wassmann, P. & K. Olli (eds), Drainage basin nutrient inputs and eutrophication: an integrated approach, 60–87 E-book in press, 309 pp. available at: http://www.ut.ee/~olli/eutr/.
- Garnier, J., L. Laroche & S. Pinault, 2006b. Determining the domestic specific loads of two wastewater plants of the Paris conurbation (France) with contrasted treatments: a step for exploring the effects of the application of the European Directive. Water Research 40: 3257–3266.PubMedCrossRefGoogle Scholar
- Houghton, J. T., L. G. Meira Filho, B. A. Callander, N. Harris, A. Kattenberg & K. Maskell (eds), 1996. Climate change 1995. The Science of Published for Intergouvernmental panel on climate change, Cambridge Univ. Press, 1–572.Google Scholar
- Poth, M. & D. D. Focht, 1985. N-15 kinetic analysis of N2O production by Nitrosomonas europaea -an examination of nitrifier denitrification. Applied & Environmental Microbiology 49: 1134–1141.Google Scholar
- Redfield, A. C., B. H. Ketchum & F. A. Richards, 1963. The influence of organisms on the composition of sea-water. In Hill, M. N. (ed.), The Sea. John Wiley & Sons, New York, 12–37.Google Scholar
- Sanchez, N., 1997. Le processus de dénitrification dans les sédiments du barrage-réservoir de la Marne: étude de sa cinétique et modélisation. Thèse Univ. P&M. Curie, 140 pp.Google Scholar
- Strahler, A. N., 1957. Quantitative analysis of watershed geomorphology. Transactions, American Geophysical Union. Vol. 38. No. 6.Google Scholar