| Summary: | Thesis (DTech. degree in Civil Engineering)--Tshwane University of Technology, 2009. === Landfills, once the panacea of municipal solid waste (MSW) disposal, is now the
pariah of MSW management strategies in developed countries. These countries,
affluent and technologically well developed, have realised that MSW disposal in
landfills is converting their scarce open spaces into unusable, unattractive areas,
which threaten public health through environmental pollution. Alternative
mechanisms are being developed and implemented to deal with the MSW once
considered to be an inevitable by-product of civilization.
As new technologies become available the populations of developing countries
have increased rapidly, large cities have mushroomed and the nature of the MSW
being generated has changed to such an extent, that nature is no longer able to
assimilate it.
Population density constitutes the chief motivation to oppose landfills. In this
respect, South Africa, with 39 people/km2, comparable with the USA (31
people/km2) but much lower than Austria (98 people/km2) and the UK (246
people/km2) appears to have sufficient space for more landfills. However,
Gauteng, as the smallest of the country's nine provinces, has a population density
of 432 people/km2, therefore for Gauteng cities such as the City of Johannesburg
(CoJ) and the City of Tshwane Metropolitan Municipality (CTMM) landfilling is no
longer a viable option.
South Africa, as a developing country, consists of first world islands scattered in a
third world environment. South Africa's per capita GDP of $5 380, places it at
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number 88 (2008) in the world ranking, together with countries such as Argentina
and Turkey (both at around $5 500). However, Gauteng, as the smallest of the
country's nine provinces, has a per capita GDP of $13 000, which is comparable to
countries such as Hungary ($11 200) and the Czech Republic ($13 900).
Although still far short of countries such as the Netherlands ($40 200) and the
USA ($44 200), it is clear that Gauteng cities should have the financial capability to
move away from landfilling to more sophisticated MSW management strategies
such as mechanical biological treatment methods.
Presently the CTMM is still landfilling all its MSW, including garden waste, with no
pre-processing or minimisation efforts. This is a result of the available capacity in
its existing landfill sites, thought to be able to satisfy the city's needs for the next
10 years. It is probable that the authorities will not wake up to the problem before
it is too late, as is the case in the adjacent CoJ, where there is virtually no landfill
space left and no future strategy in place.
This study first identified and evaluated technologies available in developed
countries for processing the various components of the MSW stream, appropriate
to local conditions, as an alternative to landfilling, to ensure that these components
will be either reused, recycled or rendered harmless to the environment before
disposal. Then most appropriate technologies for the CTMM were selected and
assembled into an optimal configuration to achieve a Zero Waste situation in the
CTMM within a decade or two. This represents a significant change in MSW
management in the CTMM: from total landfill to zero waste. The level of insight
and the degree of change, proposed in the study, will avert a MSW crisis in a few
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years’ time by the implementation of an affordable and sustainable MSW management model.
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