Municipal solid waste entombed in landfills will produce pollution in the form of landfill gas and leachate when the barriers fail in the long term. Bioreactor landfills are an alternative solution to avoid such negative impacts and to achieve a more stable residue, the so-called Final Storage Quality (FSQ) of residues. However, until now the main technical problem faced by landfill operators in bioreactor landfill operation is homogenous liquid distribution within the waste mass.
The main objective of this thesis was to achieve a FSQ status of waste, through laboratory and pilot-scale experiments, that complies with the Waste Acceptance Criteria (WAC) of the European Landfill Directive for inert waste. This thesis focused on the interaction and modification of the factors controlling the waste stabilisation process in a bioreactor landfill. The results revealed that within a year of operation biological stabilisation can be achieved, but not FSQ status. However, residues were close to comply with such stringent criteria. Buffer and septage addition had a positive effect on the waste stabilisation process by reducing biogas production lag-phase and risks associated with pathogen contamination. Also the use of coarse materials had a positive impact on the waste stabilisation process, especially as homogenous mixtures. The presence of Anammox bacteria - shown for the first time to be active in a bioreactor landfill - suggested that it could have contributed substantially to the removal of nitrogen, which has been identified as the main parameter to jeopardise the achievement of FSQ status.
In conclusion, this research reduced our current gaps-in-knowledge and offered feasible technical alternatives to control and steer the processes occurring in a bioreactor landfill aiming to achieve FSQ status of residues.
Table of Contents
2. Achieving "Final Storage Quality" of MSW in Pilot Scale Bioreactor Landfills
3. Alternative Treatment for Septic Tank Sludge: Co-disposal with MSW in Bioreactor Landfill Simulators
4. The Effect of Hydraulic Conditions on Waste Stabilisation in Bioreactor Landfill Simulators
5. Ammonium Release and Anammox as an Option for its Removal in Bioreactor Landfill Simulators
6. Mathematical Simulation of Carbon and Nitrogen Transformations in Bioreactor Simulators
7. Conclusions and Outlook
Roberto Valencia Vazquez (1974) graduated in Civil Engineering at Instituto Tecnologico de Durango, Mexico (1998). Afer graduation, he worked for a private construction company developing residential suburbs. In October 1999, he joined the MSc program at UNESCI-IHE in Delft where he obtained his MSc degree in Environmental Science and Technology, followed by the PhD program at UNESCO-IHE Delft.