Before it is possible to predict the impact of human activities
on the natural environment it is necessary to understand the
forces that drive and, therefore, control that environment. This
paper is concerned with the freshwater component of the aquatic
environment. The driving forces involved (some of which are
under man:s control) can be divided into the physical and the
chemical, but the response is, almost entirely, biological. Although
most impacts of the food processing industry might be
perceived to be on running waters, this is not always the case, but
we can apply the same basic rules to both static and running
waters. The physical forces that determine how a lake functions
are as follows. In early spring, in the temperate zone, the temperature
of the surface water in lakes rises and the sunlight input
increases. This results in strati5cation of the water body. The
cooler, deeper water is separated, physically, by gravity. This
isolated water plays a very di4erent role in the function of the
lake and is analogous to how a river works. Man:s activities drive
these systems by our input of inorganic and organic substances.
The inorganic inputs, particularly of phosphorus, stimulate undesirable
algal growths, some of which may produce particularly
dangerous toxins. We must now accept that climate change,
driven by man, will exacerbate these problems. Organic inputs
from the food industry, i.e., carbohydrates, lipids, and proteins,
will all impact lakes and rivers by increasing the biological
oxygen demand. The worst case scenario is total loss of oxygen
from the water as a result of microbial activity. Lipids create the
greatest oxygen demand but carbohydrates (more easily biodegradable)
also result in unsightly 99sewage fungus.:: Protein waste
can be degraded to produce ammonia and sul5de, both of which
produce toxicity problems. Bioremediation processes, particularly
phytoremediation, can alleviate these problems in a coste4ective
manner and this paper will address these options. (