Page 701 - Fundamentals of Water Treatment Unit Processes : Physical, Chemical, and Biological

656 Fundamentals of Water Treatment Unit Processes: Physical, Chemical, and Biological

ACKNOWLEDGMENTS Corona
1. A faint glow adjacent to the surface of an elec-
Kevin Gertig, Water Resources & Treatment Operations
trical conductor at high voltage (www.merriam-
Manager, Fort Collins Utilities, and formerly Superintendent,
webster.com, 2003).
Fort Collins Water Treatment Facility (WTF), helped in
2. An electrical discharge effect that causes ioniza-
understanding, chlorine dioxide generation and application,
tion of oxygen and the formation of ozone, O 3
and was available to clarify practices used at the plant. (Symons et al., 2000, p. 93).
Also, Dr. Dean Gregory, CDG Environmental, Bethle-
Critical point: Point identified on p–T diagram where for
hem, Pennsylvania, was available to clarify issues related
p > p c and T > T c , the liquid and gas phases no
to chlorine dioxide generation. Dr. Gregory is based in
longer exist. For water, the critical point is:
Denver, Colorado, and conducted his master’s thesis
(T c ¼ 3748C, p c ¼ 218 atm) (Silberberg, 1996,
research on oxidation of Mn 2þ while employed at the Fort
p. 451).
Collins WTPF.
DARPA: Defense Advance Research Project Agency (U.S.
Dr. Earnest Gloyna gave permission (2010) to use his
Department of Defense).
photograph as did Dr. Michael Modell (2010). Also, both
Dielectric: A nonconductor of direct electric current (http:==
Dr. Gloyna and Dr. Modell provided several of their
www.merriam-webster.com, 2003).
published papers, at the request of the author, that were
EPA: U.S. Environmental Protection Agency. The agency
used in the development of the sections on SCWO. Dr.
was created by Executive Order of the President on
Lixiong Li provided leads on publications from the
December 2, 1970 to consolidate various environ-
period that he was associated with Dr. Gloyna in research
mental regulatory functions, for example, water pol-
(1988–1998).
lution control, air pollution, pesticides, etc., into a
single administrative agency.
Fenton oxidation: A sequence of redox reactions that form
GLOSSARY
Fe complexes initially, with radical intermediates of
Advanced oxidation processes (AOP) HOO . ,HO . , and O 2 .
.
1. Oxidation processes based on generation of Fenton’s reagent: A ferrous salt, for example, ferrous
hydroxyl radical intermediates. Combinations sulfate, Fe(SO 4 ), that acts as a catalyst for the
based on H 2 O 2 ,O 3 , and UV have been investi- production of hydroxyl radicals, . OH, from hydro-
gated to a great extent (Bull and Zeff, 1992, gen peroxide, H 2 O 2 . During the reaction, the
p. 27). ferrous salt is oxidized to the ferric form and can
2. Oxidative degradation reactions by HO . and HO 2 . participate in other chemical reactions, such as
and other less important radicals in solution gen- coagulation or metal complexation (Symons et al.
erated by various methods, for example, O 3 =UV, 2000, p. 157).
Free radical: Atoms or groups of atoms with an unpaired
H 2 O 2 =UV, and O 3 =H 2 O 2 =UV photolysis and TiO 2
mediated photocatalysis in aqueous solution or valence electron, which causes high reactivity
photo-assisted Fenton processes (Kiwi et al., (Carlson, 1992, p. 2).
2000, p. 2162). In all of the foregoing, the OH Geosmin: trans-1,10-Dimethyl-trans-9-decalol, a taste and
radical is thought to be the major reactive inter- odor causing compound that could be present in
mediate responsible for organic substrate oxida- ambient waters (Metropolitan Water District of
tion (Glaze et al., 1993). Southern California, and James M. Montgomery
AWTR: Advanced Waste Treatment Research program of Consulting Engineers, Inc., 1991, pp. 3–5).
the Division of Water Supply and Pollution Control, MIB: 2-methylisoborneol, a taste and odor causing com-
U.S. Public Health Service. The Division of Water pound that could be present in ambient waters (Met-
Supply and Pollution Control was the agency ropolitan Water District of Southern California, and
involved in wastewater treatment research before James M. Montgomery Consulting Engineers, Inc.,
being transferred to the Department of the Interior 1991, pp. 3–5).
in 1966 and before the formation of EPA in 1970. NTP: Normal temperature and pressure, that is, T ¼ 08C,
The AWTR program was active during the 1960s p ¼ 1.00 atm. NTP is common in European
and was instrumental in the development of many literature. See also STP, which is common to the
wastewater treatment processes, for example, United States.
adsorption, electrodialysis, reverse osmosis, distilla- Oxidation: A reaction in which a loss of electrons occurs,
tion, freezing, ion-exchange, oxidation, etc., that accompanied by an increase in oxidation number
were not common before the advent of the program. (Silberberg, 1996, p. G-13).
The program was administered from the USPHS Taft Oxidation number (O.N.): A number determined by a set
Sanitary Engineering Center, Cincinnati, Ohio. The of rules equal to the number of charges a bonded
program functioned through both contracts and atom would have if electrons were held completely
in-house research (Anon., 1965). by the atom that attracts them more strongly