Contaminated Land and Bioremediation - Environmental Biotechnology: Theory and Application - page 96

rather than the geographical location of the work or the level of complexity of
the technology used, as in the previous cases. In addition, it can also be relatively
easily extended to take account of any given technology.
Process Integration
However they are classified, the fact remains that all the individual technolo-
gies available each have their limitations. As a result, one potential means of
enhancing remediation effectiveness which has received increasing attention is
the use of a combination approach, integrating different processes to provide an
overall treatment. The widespread application of this originated in the USA and
the related terms used to describe it, 'bundled technologies' or 'treatment trains'
have quickly become commonly used elsewhere. The goal of process integration
can be achieved by combining both different fundamental technologies (e.g. bio-
logical and chemical) and sequences of in situ or ex situ , intensive or extensive
regimes of processing. In many respects, such a 'pick-and-mix' attitude makes
the whole approach to cleaning up land far more flexible. The enhanced abil-
ity this confers for individually responsive interventions stands as one of the key
factors in its wider potential uptake. In this way, for example, fast-response appli-
cations can be targeted to bring about a swift initial remediation impact where
appropriate, switching over to less engineered or resource-hungry technologies
for the long-haul to achieve full and final treatment.
As has been mentioned before, commercial applicability lies at the centre of
biotechnology, and process integration has clear economic implications beyond
its ability simply to increase the range of achievable remediation. One of the most
significant of these is that complex contamination scenarios can be treated more
cheaply, by the integrated combination of lower cost techniques. This opens
up the way for higher cost individual methods to be used only where abso-
lutely necessary, for example in the case of major contamination events or acute
pollution incidents. With limited resources typically available for remediation
work, treatment trains offer the possibility of maximising their utilisation by
enabling responsible management decisions to be made on the basis of meaning-
ful cost/benefit analysis.
This is an important area for the future, particularly since increased experience
of land remediation successes has removed many of the negative perceptions
which were previously commonplace over efficiency, speed of treatment and
general acceptability. For many years remediation techniques, and bioremedia-
tion especially, were seen in a number of countries as just too costly compared
with landfill. As changes in waste legislation in several of these regions have
driven up the cost of tipping and begun to restrict the amount of biodegradable
material entering landfills, the balance has swung the other way, making remedi-
ation the cheaper option. There is a certain irony that the very alternative which
for so long held back the development of remediation should now provide such a