Thesis (M.Sc.Eng.)-University of Natal,Durban, 2002.Due to the spread of urbanisation and increased environmental awareness,
odour has become a major problem in communities surrounding landfills. The aim
of this research was to investigate odour emissions from landfills and develop a
management tool that operators could use to assist in minimising the impacts of
odour. The management tool would be in the form of real-time predictions of
odour concentrations in the vicinity of a source. The Bisasar Road landfill in
Springfield, Durban was a case study site for the research.
The methodologies used in this project can be divided into three broad
categories. Firstly, flow visualisation experiments were conducted on the case
study site to investigate the effects of complex terrain and the results compared
to predictions from a dispersion model. Secondly, source characterisation was
done on-site. Sources of odour were identified using a portable odour monitor
(Electronic nose). Sources of odour were then sampled using sorbent tubes and
analysis done using Gas Chromatography - Mass Spectrometry. Thirdly,
numerical dispersion modelling was done. Five available dispersion models were
assessed and compared against one another in order to select the most suitable
model for this application. A software management tool or 'Odour Management
System' (OMS), was designed and implemented on a computer at the Bisasar
Road landfill.
Qualitative results of the flow visualisation experiments show that terrain does
have an effect on a dispersing plume path for short-range predictions.
Comparisons between the flow experiments and model predictions are
qualitatively consistent. Quantitative results were not obtained for the emission
flow rate and emission concentration of landfill gas. The chemical composition of
the fresh waste gas was determined. ADMSTM(Advanced Dispersion Modelling
System) was found to be the most suitable dispersion model for this application.
The OMS has been installed on-site to produce odour concentration graphics
every ten minutes. A fence line odour control misting system has been installed
along approximately 600 metres of the landfill border based on work done as part
of this project. Weather conditions and information provided by the OMS, assist in
running the odour control system economically