Biotechnology and Waste - Environmental Biotechnology: Theory and Application - page 186

users have begun to investigate assessment based on microbiological profiling.
Pioneering work in the USA, by BBC Laboratories of Arizona, has led to the
development of the first predictive tool for the value of a compost as a soil micro-
bial inoculant, based on the concentrations of six key classes of micro-organisms
present (Bess 1999). The marketing of biowaste-derived products is made more
difficult by a number of factors which lie outside of the scope of this work, most
particularly a lack of a recognised and universally agreed standard. The applica-
tion of microbiological criteria, in conjunction with the likes of mineral analysis
and maturity assessment, could lead to significantly better overall characterisation
of composts. Moreover, there seems no reason why this approach should not be
extended to all biowaste-derived soil amendments, enabling direct comparisons
to be made and the suitability of any given product for a particular use to be
measured objectively.
Applying Composting to Waste Management
Composting has an appeal to local authorities needing to meet diversion targets
while keeping a watch on their budgets, since it is relatively simple and does
not demand particularly high resource investment, either to set up or run. As
a consequence, many of the initiatives instigated to deal with biowaste have
been based on composting of one form or another. In the broadest of terms, such
schemes fall into one of two categories, namely, home composting, or centralised
facilities. The focus of this section will fall on the latter, as a more representative
application of biotechnology, though to set this in context, it is worth giving a
brief outline of the former.
Home composting
Home-based systems differ little in reality from the traditional gardener's approach,
putting biodegradable material into a heap or, more typically a bin, often provided
free or at a subsidised price, by the local council. Though this does have the
advantage of directly involving people in the disposal of their own waste and
the informality of this approach has its own advantages, such schemes are not
without certain drawbacks. To work, these initiatives draw heavily on householder
goodwill and competence, not to mention a good choice of bin and simply making
the means available does not, of course, ensure that it will be used. Anecdotal
evidence suggests that many bins lie unused within two years, once the initial
enthusiasm wears off, and an investigation into Luton's trial scheme suggests
that home composting may make little difference to the overall amount of waste
generated (Wright 1998). The kind of instant minimisation popularly supposed
would seem to be far from guaranteed.
One clear advantage that household composters do have, however, is the ability
to control very closely what goes into their system. This avoids both the issues