266 Environmental Biotechnology
Case Study 10.1 Integrated Pollution Control (Hoy, Orkney)
While there are many examples available of the use of biotechnology to mitigate
environmental contamination, perhaps one of the most interesting illustrations lies
in the integration of pollution control between a controlled internal environment
and the outside world.
Fish farming has often been the target of much criticism for its effect on local
waters, typically being blamed for pollution and reduced natural biodiversity or
indicted as a reservoir of disease to the detriment of wild populations. Leaving aside
the fact that many of these accusations are simply unfounded, the industry itself
has a clear vested interest in the sustainable use of water. Accordingly, many fish
farmers have developed approaches to their business which reflect a very practical
concern for environmental protection. The Rackwick Hatchery on the island of Hoy,
Orkney, typifies the sort of best practice which can be achieved by even relatively
modest operations.
Water recycles through the growing tanks, returning to a central sump from
which it passes into a biofiltration system designed by the proprietor, John Eccles,
to maximise treatment efficiency while minimising energy use. As it trickles down
through the filter elements, nitrates, nitrites and ammonia are removed and the water
is re-oxygenated beyond the requirements of the resident biofilm microbes, thereby
partially reconditioning it for reuse in the fish-growing units. The arrangement of
the water return, which deliberately encourages surface splashing, continues this
process with a net result that the fish farm has a significantly reduced requirement
for abstracted fresh water.
Independent monitoring of the adjacent Rackwick burn by the Scottish Environ-
mental Protection Agency (SEPA) has established that there is virtually no difference
in water quality between upstream and downstream of the facility, the small vari-
ance noted, lying well below the relevant acceptable limits. By integrating good
husbandry, conventional UV sanitisation techniques and effective bioengineering,
the fish farm has managed to meet a number of environmental goals, achieving low
resources demand in terms of energy and water, together with effective pollution
control, without compromising the internal conditions necessary for commercial
production of high-quality fish protein.Case Study 10.2 Practical Bioenergy (Canada and the USA)
Attempts to derive energy from waste biomass have often been criticised over the
years, typically being cast as incineration by another name. Forestry and wood
wastes in particular, lend themselves to true ‘thermal recycling’, but this can only be
a justifiable environmental option when wider considerations are taken into account.
An example of this is provided by the advances made by Talbott’s Heating, Stafford
UK, in meeting stringent pollution control targets on the international market. Having
been manufacturing and exporting systems for some 30 years, the company has
seen considerable changes in regulation and continuous research and development
has enabled them to meet all necessary requirements. In addition to the uniqueContinued on page 267