The study undertaken has focal points in:
of landfilled MSW
of a disruption technique
of physical disruption in practice
of the impact of vibrations on LFG formation
The results from the waste characterisation indicate
that a great variation with regard to the extent of degradation may occur over a
ten-year period. In some cases the degradation of organic material is quite
complete after ten years whereas a substantial remaining potential for gas
formation can be found in other cases. The degradation can be slowed by
microbiological process conditions. These processes may be influenced through
the fluid phases if the design of the landfill permits it. It could also be
possible to influence flow conditions after the construction phase of the
landfill through physical measures.
Different methods to influence
landfill flow conditions have been studied and, as a prime choice, dynamite
blasting has been identified. Following a series of blasting tests for method
development purposes, in situ blasting at test cells were performed twice. An
initial gas development could be noted, but because of high groundwater level in
the landfill, only the short-term impact could be observed.
Gas collection data from landfills thought to be
influenced by vibrations from on site traffic or nearby blasting activities were
investigated using multivariate statistical methods, but no strong correlations
could be found.
In conclusion it has been shown that there is a remaining degradation potential at some landfills or parts of landfills that could possibly be realized faster with the aid of physical disruption. Feasible disruption techniques exists and their merits now need assessment in large scale experiments.