A NUMERICAL MODEL FOR DENITRIFICATION OF MUNICIPAL LANDFILL LEACHATE AND PARAMETRIC ANALYSIS ON DENITRIFICATION CONTROLLING FACTORS

In order to develop a new technology for denitrifying leachate by using fatty acid compounds (FAC), a water quality model was developed by considering balances of nitrogen, dissolved oxygen, carbon, phosphorus and denitrification bacteria involved in leachate denitrification. FAC is expected to function not only as a donor of hydrogen and carbon to nourish and activate denitrification bacteria but also as a reducer of nitrified leachate. Prior to the present study, performance of FAC for denitrifying leachate was confirmed in a laboratory experiment under various conditions of leachate loading discharge and nutrients. Time-dependent behaviours of water quality observed in the experiment were successfully reproduced by the model with high accuracy. The model also provides a solution of denitrification performance as a function of hydraulic retention time, HRT. The proposed water quality model is expected to be a useful engineering tool for planning, designing and constructing a cost-saving leachate treatment system.