The Treatment of
Refinery Waste Water with Particular
Consideration of Phenolic Streams
WILHELM STECK, Technologist
German Shell Company
Hamburg, Germany
INTRODUCTION
Although the processing of mineral oils in refineries is nowadays carried out
on a world-wide scale, the consequence of this activity in relation to the prevention of water and air pollution vary from country to country. This difference in
importance depends on the relevant geographical, orographical, and meteorological conditions,   and on the density of population, to mention but a few factors.
Thus the comments to be given on the treatment of refinery waste water will
relate chiefly to conditions in Germany. That is, to a highly industrialized but
compact country in which industry and population live side by side. The rivers
which can serve to carry away waste water are relatively small and their flow also
fluctuates considerably. Generally speaking, there is enough ground water to
serve the needs of the population, but this is not present everywhere nor is it always of satisfactory quality, so thatthe protection of existing supplies is desirable,
particularly in view of the increasing demand. Then there is another important
point: The meteorological conditions are also by no means ideal, particularly inland. There are industrial agglomerations in regions where there is absolute calm
for more than 25 per cent of the year, increasing to more than 40 per cent in certain months. It can, therefore, be understood that all the measures for the treatment of waste water should also be considered from the point of view of prevention of air pollution.
The waste water discharged from the various processing plants and auxiliary
installations contains a wide variety of pollutants. Nevertheless, every effort will
be made to consider the problem of the treatment of these different waste water
streams as a whole in order to achieve a technically, and therefore economically,
optimum solution. The necessity of such an approach arises from the stringent
requirements now set for the quality of waste water, which make the most central
possible treatment of waste water essential for the reduction of costs. Such central
treatment of waste water may also prove desirable if only a few or even just a
single outlet to the receiving water is permitted by the authorities, in order to
facilitate a check on the waste water.
As a result of this situation efforts are being made everywhere to reduce as
far as possible the volume of waste water to be treated. This is made possible by
the extensive separation of clean and polluted water in refinery waste water systems. Thus, for example, clean cooling water will never be combined with
polluted water. Furthermore, when choosing operating processes, preference will
be given to those which pollute the least water while still giving the same production. Here, for example, the regenerative washing processes and also the increasing use of circulating cooling water and air cooling should be mentioned.
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