176 Environmental Biotechnology
Table 8.1 A comparison of selected national waste management arrangements, recy-
cling rates and MSW biowaste component
Country Landfill (%) Incineration (%) Recycled (%) Biowaste (%)
Austria 65 11 24 27
Belgium 43 54 3 47
Canada 67 4 29 34
Denmark 20 55 25 37
Finland 66 4 30 33
France 59 33 8 30
Germany 46 36 18 30
Netherlands 30 42 28 35
Japan 21 74 5 26
Norway 68 18 14 35
Sweden 34 47 19 38
Switzerland 11 47 42 30
UK 85 9 6 30
USA 61 15 24 32
Sources: IEA Bioenergy, European Commission & relevant Embassies.
incineration. Different countries and administrations have favoured one or the
other at various times and, as with all things to do with waste, local custom and
circumstance have played a major part in shaping the current status quo. While
it is beyond the scope of the present discussion to examine this in any depth,
Table 8.1 may help to provide some indication of the wider situation.
Although there has been considerable development in incineration technology
over the years and today’s facilities, with their energy recovery, power generation
and district heating potential, are a far cry from the simple smoking stacks of old,
for biological origin waste, mass burn incinerators cannot be viewed as the ideal
solution. Hence, while the incineration v. landfill argument still rages, and has
been revisited with renewed vigour in some circles in the light of the implications
of recent European legislation on landfill, the fact remains that, at least from the
standpoint of biowaste, both are nothing more than disposal routes. Significant
amounts of wet organic material, which is itself largely composed of water to
begin with, may be an inconvenience to the incinerator operator; the situation in
landfill is worse.
Landfill
Left to its own devices, all discarded biological waste gradually undergoes a natu-
ral process of biodegradation, typically beginning with autolysis and culminating
in putrefaction. The speed at which this progresses is governed by a number of
factors such as the nature and freshness of the material, the temperature, mois-
ture and so on. When this happens in the open air, or in the upper levels of
the soil, decomposition is aerobic, the organic material being mineralised and
carbon dioxide (CO 2 ) released as the major gaseous product. However, though