Page 64 - Fundamentals of Water Treatment Unit Processes : Physical, Chemical, and Biological

Water Treatment 19

State of water: The quality characteristics of a given water concentration of particles) is a process by this defin-
volume, including concentrations of mineral sus- ition as is even pumping (which causes a pressure
pended matter, ions, molecules, microorganisms, change).
and such parameters as temperature, pH, specific
electrical conductance, etc. REFERENCES
Technology: (1) An anthropogenic device contrived to
accomplish a task. The rapid filtration process is Carson, R., Silent Spring, Houghton Mifflin Company, Boston, MA,
1962.
encompassed within the filtration technology,
Champlin, T. L. and Hendricks, D. W., Treatment train modeling for
which includes all of the appurtenances to make it
aqueous contaminants, Volume II, Matrix of Contaminants
function to remove suspended particles to a specified and Treatment Technologies, Environmental Engineering
concentration level. (2) A collection of devices con- Technical Report 53-2415-93-2 (for U.S. Army Construction
trived to accomplish one or more tasks, as in a Engineering Research Laboratory), Department of Civil
system. Water treatment technology includes all of Engineering, Colorado State University, Fort Collins, CO,
the processes and relevant appurtenances to produce May 1993.
City of Colorado Springs, Two handouts to visitors: The first
potable water.
describes the sewage treatment plant and its history and the
Technology: A technology is a means to implement a unit
second describes the tertiary treatment plant, Department of
process. Any number of technology forms may be Public Utilities, City of Colorado Springs, Fort Collins, CO,
devised to embody a unit process. For example, a c. 1972.
biofilm reactor may be embodied in several forms, Commonwealth of Massachusetts, Proud Heritage—A Review of
including a traditional trickling filter, a deep-bed the Lawrence Experiment Station Past, Present, and Future,
trickling filter, a rotating disk reactor, a traditional Commonwealth of Massachusetts, 1953.
Lagnese, J. F., Teaching environmental engineering design—A prac-
slow sand filter, a bio-filter for removal of natural
titioner’s perspective, Environmental Engineer, 36(1):8–12,
organic matter (NOM), etc.
32, January 2000.
Treatment: Subjecting water to the unit processes of a treat- Letterman, R. D., Water Quality and Treatment, 5th edn., American
ment train. Water Works Association, McGraw-Hill, New York, 1999.
Treatment train: An aggregation of unit processes. Ludwig, H. F., Adventures in Consulting Engineering, Seatec Inter-
Unit operation: A term used in chemical engineering to national Publications, Bangkok, Thailand, 1985.
designate a physical change, e.g., pumping, screen- Okun, D. A., Regionalization of Water Management—A Revolution
in England and Wales, Applied Science Publishers, Inc., Lon-
ing, sedimentation, filtration, etc. The term is not
don, U.K., 1977.
used in this book in favor of using a single term,
Ongerth, H. J., Personal communication, September 20, 1999.
‘‘unit process.’’ [Henry Ongerth was Chief, Bureau of Sanitary Engineering,
Unit process (chemical engineering): A term used in State of California, retiring about 1980. He started with the
chemical engineering to designate a chemical Bureau from the time of his graduation at the University of
change, e.g., oxidation, precipitation, disinfection, California in 1936.]
and biological treatment. The chemical engineering Qasim, S. R., Motley, E. M., and Zhu, G., Water Works Engineer-
ing—Planning, Design & Operation, Prentice-Hall,
literature is not unequivocal in the use of the two
New Delhi, India, 2006.
terms ‘‘unit operation’’ and ‘‘unit process,’’ but the
Rich, L. G., Unit Operations of Sanitary Engineering, John Wiley &
definitions given seem to capture the sense of Sons, New York, 1961.
how they are used. Rich, L. G., Unit Processes of Sanitary Engineering, John Wiley &
Unit process (this book): As used in this book, the term Sons, New York, Rich, 1963.
‘‘unit process’’ means an engineered effect that Sanks, R. L. (Ed.), Water Treatment Plant Design, Ann Arbor
causes a ‘‘state change.’’ The sense is the same as in Science Publishers, Inc., Ann Arbor, MI, 1978.
Servos, J. W., Physical Chemistry from Ostwald to Pauling:
chemical engineering except that a ‘‘state change’’ is
The Making of a Science in America, Princeton University
much broader that being restricted to a ‘‘chemical
Press, Princeton, NJ, 1990.
change.’’ A state change may include not only chem- Symons, G. E., The origins of environmental engineering: Prologue
ical change, but pressure change, temperature change, to the 20th century, Journal of the New England Water Works
concentration change, etc. Thus, settling (change in Association, 115(4):253–287, December 2001.