Modelling of nitrogen release from MBT waste

Area of Science:

• Environmental Engineering
• Geochemistry
• Waste Management

Background:

• Nitrogen dynamics in landfills are complex, influencing environmental impact.
• Mechanical-biologically pretreated (MBP) waste presents unique challenges for nitrogen management.
• Long-term prediction of nitrogen behavior is crucial for sustainable landfill operation.

Purpose of the Study:

• To introduce the LaNDy model for evaluating long-term nitrogen behavior in MBP waste landfills.
• To integrate hydraulic, thermal, and biogeochemical processes into a unified model.
• To provide a tool for predicting landfill temperature and leachate ammonium concentrations.

Main Methods:

• Developed the LaNDy model, combining Richard's equation for hydraulics with 1D heat flow.
• Incorporated kinetics of biological degradation, gas diffusion, nitrification, and denitrification.
• Utilized a temperature-dependent N mineralization sub-model based on literature and experimental data.

Main Results:

• Demonstrated the LaNDy model's capability to predict long-term nitrogen dynamics.
• Presented examples of predicted temperature distribution and leachate ammonium concentrations.
• Showcased the model's sensitivity to landfill size, age, and waste hydraulic conductivity.

Conclusions:

• The LaNDy model offers a robust mathematical tool for assessing landfill nitrogen behavior.
• The model aids in understanding the long-term environmental impact of MBP waste.
• LaNDy provides valuable insights for optimizing landfill management strategies.