Treatment by Freezing
AMOS J. ALTER, Environmental Research Engineer
Alaska Department of Health and Welfare
College, Alaska
INTRODUCTION
Freezing may be one of the most useful processes for conditioning water and
waste water. Surprisingly little is known about details of the process and even less is
known about applying the process to water and waste treatment.
In temperate climate engineering practice, the process has appeared uneconomical. Energy requirements have appeared excessive. An emerging multi-billion dollar
polar push for petroleum and other resources creates new viewpoints. It raises
questions about methodology for permanent occupation and use of cold regions.
This is a different, yet no less compelling, reason for economical and competitive
solution to cold region problems. Profit as well as other reasons is now motivating
decisions made on cold region development. Relatively high cost modification and
subsidy of temperate climate water and waste treatment practice is not competitive;
cold region engineering solutions are needed for cold region problems.
In addition to saving money, there are other reasons for learning more about
freezing as a treatment process.
Cold is a significant resource available for use throughout a large portion
of the land mass of the northern hemisphere.
A low temperature view point is necessary for full understanding of the
limits of applicability of conventional processes (1, 2).
Present treatment technology is largely the result of temperate climate experience (3). When facilities are built for waste treatment under cold region conditions, we commonly extrapolate from temperate climate experience. Extrapolation
allows little or no provision for input of new information, even though new information might be of determinative significance. In-depth studies are indicated to
determine effectiveness, methodology, application, and economics of water and waste
treatment by the freezing process.
In temperate climate engineering practice, conventional water and waste treatment processes (sedimentation, coagulation, filtration, aeration, digestion, etc.) are
often for cold region use varied slightly (4). They may be varied to reduce cost or
gain efficiency. Process facilities may be reduced or increased in size to compensate
for temperature effects. Heat or insulation or both may be used to keep facilities
from freezing. But in the optimization technique of selecting a specific design for a
cold region site, appropriateness of the basic concept for cold region use may be unquestioned.
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