Nitrogen dynamics in composting

This paper describes the validation of a mathematical model of the nitrogen dynamics in composting processes. The mathematical model, which was develo ped to simulate the processes of substrate decomposition and ammonia evolut ion, links the dynamics of microbial populations to the transformation of c arbon and nitrogen during the initial. high rate stage of composting. Labor atory-scale experiments were carried out to validate the model. The influen ce of the form or availability of carbon on ammonia volatilization was inve stigated. The addition of molasses decreased cumulative ammonia emissions w hile the addition of office paper did not. Experimental results were compar ed with the output from the simulation model and were in good agreement, pa rticularly during the initial stage of composting. The model will be used t o investigate the sensitivity of ammonia evolution to different process var iables in order to derive strategies for nitrogen conservation during compo sting.