< Back to previous page

Publication

To mine or not to mine: a review of the effects of waste composition, time and long term impacts of landfills in the decision making for ELFM

Book Contribution - Book Chapter Conference Contribution

Several studies have addressed the environmental impacts of landfill sites and are all dependent on the assumptions, system boundaries and modelling choices made. Results are, in particular, influenced by the waste composition, the geographic site and the time horizon chosen for the impact assessment. This study will include a review of literature and discuss the importance of waste composition and the temporal boundaries chosen on the impacts of landfill sites and on the profitability of ELFM. Waste composition has proved to affect significantly the impacts of landfills. For example, low organic waste can lead to reduced leachate and LFG emissions and impacts. These results support the current EU regulative framework requiring the ban of biodegradable waste from landfills by 2030, together with a reduction in the landfilling of recyclable fractions of 65%. In this framework, the profitability of Enhanced Landfill Mining (ELFM) needs also to be analysed in relation to parameters as waste composition and time horizon. Studies have shown how ELFM can, in some cases, result in not being a profitable solution when considering low carbon waste with inert materials such as soil, fines and plastics as major components. The environmental impacts of resource recovery processes would, in fact, be higher than the impacts related to the emissions of the landfill site alone. However, these considerations do not take into account the long term emission potentials of substances such as heavy metals, ammonium, COD, which can also be found in significant amounts in low carbon waste. Longer time horizons should then be considered when addressing landfill impacts and the profitability of landfill mining. Inert materials such as glass, ceramics, PVC and metals, decompose very slowly and their impacts can mostly be accounted for on a long term perspective. Therefore, the paper aims at reviewing how time and site-specific parameters affect the environmental impacts of landfills. Focus of the paper are the long-term emission potential of landfills and, in particular, of leachate, to highlight the need to obtain time-dependent emission profiles for more consistent environmental impact assessments of landfills on a long-term perspective.
Book: Proceedings of the 4th International Symposium on Enhanced Landfill Mining
Pages: 379 - 388
Publication year:2018
Accessibility:Closed