Background
Adequate management of municipal solid waste (MSW)
is essential for the health of urban residents, for the protection
of the environment and the conservation of
resources, and therefore for the sustainability of any city.
In its widest sense, the activities associated with the
management of MSW include waste handling, collection
and transport, treatment, recovery of materials and energy,
and final disposal (Figure 1). In most developed
countries, each of these stages, mainly due to legal regulations,
occurs as part of the system.
In Germany, the amount of waste disposed of has been
reduced considerably within the last years due to the fact
that since 2005 the landfilling of untreated waste is no
longer allowed. Instead, mechanical, biological, and/or
thermal treatment measures have to be carried out before
final disposal. This is the result of a planned waste
management strategy initiated by the Government more
than 20 years ago [2], of which the fundamental objectives
are (a) the reduction of waste generation, (b) the
prohibition of uncontrolled discarding, discharge, and
disposal of waste, and (c) the promotion of integrated
waste management systems following the steps: avoidance,
recycling, and conversion of waste with a preference
to material and energy recovery [2].