Nitrogen metabolism in landfills and its modelling

Nitrogen is one of the compounds which pollute leachates from municipal solid waste landfills over a long period of time. In laboratory scale tests a significant reduction of nitrogen emissions could be observed as a consequence of biological waste pre-treatment. During waste composting persistent organic substances, humic substances, are synthesised. If and how nitrogen is incorporated in these humic substances, and what kind of consequences this has on the emissions behaviour of landfills has not been investigated in detail to date. Within the scope of the submitted project the boundary conditions which promote nitrogen immobilisation during biological waste pre-treatment will be investigated in laboratory scale tests. Non pre-treated and biologically pre- treated waste will be installed in landfill simulation reactors and their emissions behaviour particularly concerning nitrogen will be comparatively studied. On the basis of the data gained in the tests a mathematical model will be developed to describe the nitrogen metabolism of landfills. Final aim of the project is a deepened understanding of the nitrogen behaviour in wastes under aerobic and anaerobic conditions and the generation of a mathematical model, that takes into consideration the complex processes of nitrogen transformation during biological treatment and subsequent landfilling and allows a realistic prognosis of the medium-term nitrogen emissions of landfills for non pre-treated and biologically pre-treated municipal solid waste.