Effects of Temperature on the Long-Term Behaviour of Waste Degradation, Emissions and Post-Closure Management Based on Landfill Simulators

ABSTRACT

A demonstration pilot with seven anaerobic landfill simulators (LSRs) was used to study the impact of temperature in the range of 20 - 46 °C on long-term landfill emissions, characteristics and tendencies, because of an evident lack of knowledge in this area. The pilot ran more than 1400 days. Higher temperatures accelerated the waste degradation and gas generation, but also resulted in higher leachate COD and NH₄-N concentrations, which will prolong the aftercare period in order to meet the effluent discharge limits. Gas generation showed the highest temperature sensitivity, 1.6- 2.8 %°C^-1, whereas COD, NH₄-N and chloride emissions were on 0.8 - 1.5 %°C^-1 level. The temperature coefficient of gas generation differs considerably from the scarce values given in landfill simulation studies, but is in accordance with hydrolysis solubilisation related behaviour and gives thus more detailed information of landfill behaviour at different temperatures. The simulator results were applied in European conditions in a typical big landfill containing mainly organic matter, giving the length of aftercare over 200 years to achieve effluent discharge limits. Within the same aftercare period (around 200 years), mesophilic conditions compromised high gas production and near lowest leachate concentrations. The in situ landfill leachate pre-treatment process and a specific leachate management system are essential in order to achieve cost-effective and shorter landfill aftercare. The results give new information for evaluation and modelling of landfill control strategies in long-term in various environmental conditions.

Keywords:

Municipal waste management, landfill simulators, long-term emissions, temperature coefficient, andfill leachate management.