Phytotechnology and Photosynthesis - Environmental Biotechnology: Theory and Application - page 143

7
Phytotechnology
and Photosynthesis
From a practical standpoint, phytotechnology is the use of plants in environmental
biotechnology applications, and draws on many of the characteristics which have
already been described. In this respect, it does not represent a single unified
technology, or even application, but rather is a wider topic, defined solely by the
effector organisms used. Thus the fundamental scope of this chapter is broader
and the uses and mechanisms described somewhat more varied than for many of
the preceding biotechnologies discussed.
Plants of one kind or another can be instrumental in the biological treatment of
a large number of substances which present many different types of environmen-
tal challenges. Accordingly, they may be used to remediate industrial pollution,
treat effluents and waste waters or solve problems of poor drainage or noise nui-
sance. The processes of bioaccumulation, phytoextraction, phytostabilisation and
rhizofiltration are collectively often referred to as phytoremediation. Although it
is sometimes useful to consider them separately, in most functional respects, they
are all aspects of the same fundamental plant processes and hence there is much
merit in viewing them as parts of a cohesive whole, rather than as distinctly dif-
ferent technologies. It is important to be aware of this, particularly when reading a
variety of other published accounts, as the inevitable similarities between descrip-
tions can sometimes lead to confusion. Moreover, the role of phyto technology is
not limited solely to phyto remediation and this discussion, as explained above,
is more deliberately inclusive of wider plant-based activities and uses.
Despite the broad spectrum of potential action exhibited by plants in this
respect, there are really only three basic mechanisms by which they achieve
the purpose desired. In essence, all phytotechnology centres on the removal and
accumulation of unwanted substances within the plant tissues themselves, their
removal and subsequent volatilisation to atmosphere or the facilitation of in-soil
treatment. Plant-based treatments make use of natural cycles within the plant
and its environment and, clearly, to be effective, the right plant must be chosen.
Inevitably, the species selected must be appropriate for the climate, and it must,
obviously, be able to survive in contact with the contamination to be able to