Abstract:
Concerns regarding climate change are becoming a driver behind legislation at both
UK and EU levels, and also on the wider, planetary scale This is the case with
emissions from landfills where the release of methane is being targeted for reduction
This thesis uses an integrative approach, incorporating concepts of hierarchy from
systems theory, to model landfill as a complex biophysical technology It assesses the
contribution to carbon deposition and global warming of landfill through changes to
that technology itself and through changes in the waste stream caused by potential
waste policies
The thesis develops an holistic, conceptual model of the landfill system, mapping
flows and transformations of carbon within that system It further develops this
conceptual model into a calculating model of landfill as a waste management
technology incorporating measurements taken to provide new data and validate
published data to calibrate the model It thus applies modelling techniques to a
biophysical technology, producing an integrated model of the landfill that allows the
knowledge gained from other research to be used to explore engineering and
operational decisions on landfills
The thesis includes results from measurements of the composition of household
waste, and of the biochemical methane potential (BMP) of fractions of that waste It
includes measurements of the residual BMP in samples of excavated waste and
measurements of gas flows
The main results suggest the following
• Early capping of landfilled waste is important in reducing the global warming
impact,
• If the rate of degradation of the waste is accelerated in the drive towards
sustainability, capping should be carried out even earlier if the global impact is not
to be increased,
• Although recycling parts of the degradable elements of the waste stream has the
effect of reducing the global impact, extensive recycling has implications for
landfill engineering
