76 Environmental Biotechnology
Adsorption
Activated carbon preferentially adsorbs organic molecules; this can be tailored
to give contaminant-specific optimum performance.
Incineration
High temperature oxidation; effective against most contaminants, but costly.
Ozonation
Use of ozone to oxidise some contaminants, like hydrogen sulphide; effective
but can be costly.
The main advantages of biotechnological approaches to the issue of air contam-
ination can be summarised as:
- competitive capital costs;
- low running costs;
- low maintenance costs;
- low noise;
- no carbon monoxide production;
- avoids high temperature requirement or explosion risk;
- safe processes with highly ‘green’ profile;
- robust and tolerant of fluctuation.
As was discussed in the first chapter, pollution control stands as one of the three
major intervention points for the application of environmental biotechnology.
Having defined some of the major principles and issues, the next chapter will
examine how they are addressed in practice. However, it must not be forgotten
that, as with all tripods, each leg is equally important; the potential contribution
to be made by the so-called ‘clean technologies’ in manufacturing should not be
overlooked. Much of the focus of environmental biotechnology centres on the
remediation of pollution or the treatment of waste products. In many respects,
this tends to form the natural constituency of the science and is, certainly, where
the bulk of practical applications have generally occurred. While the benefits
of the controlled biodegradation of unwanted wastes or contaminants is clear,
this does typify ‘end-of-pipe’ thinking and has led, to some extent justifiably,
to the criticism that it merely represents moving the problem from one place to
another. Another option to deal with both these ongoing problems is, simply, to
avoid their production in the first place and while this may seem over-idealistic
in some aspects, it does have a clear and logical appeal. Throughout this book,
‘environmental’ biotechnology is defined in the broad sense of the utilisation
of applied biological methods to the benefit of the environment. Thus, any use
of the life sciences which removes, remediates or obviates contamination of the
biosphere falls firmly within its remit andaprioriaction, to avoid the problem in