TM 5-814-8
tive is receiving attention as an alternate, it
carbon may be required to reduce chlorine residu-
remains unattractive due to high capital and
als prior to discharge.
(2) Alkaline chlorination. Use of breakpoint
operating costs for other than very small sys-
tems.
chlorination to oxidize ammonia to nitrogen gas,
(6) Ionizing radiation. Application of ionizing
which is released to the atmosphere, has been
radiation as an alternative to chlorine or ozone for
used in water treatment for numerous years. the
process requires large chlorine dosages (8 to 10
disinfecting wastewater and as an alternative to
heat for disinfecting sludge is now in the develop-
mg/L chlorine for each mg/L of ammonia oxidized)
ment and demonstration stage in the U.S. and in
resulting in high operating costs. Adjustment of
Europe. Both gamma rays and high energy elec-
pH is often required and formation of complex
trons are being evaluated. The technical feasibil-
organic-nitrogen-chlorine compounds have been
ity has been established but data to assess the
harmful environmental effects. Application will be
limited to removal of trace ammonia after some
cost-effectiveness are not yet available. Experi-
ence to date with ionizing radiation indicates that
other ammonia removal process.
applications will be characterized by relatively
(3) Ozonation. An alternative to chlorine is
high capital costs and moderate-to-low operating
use of another disinfectant such as ozone. Manu-
facturer's literature indicate over 500 water treat-
costs. In addition to destroying microorganisms
ment plants in Europe use ozone for disinfection.
in wastewater and sludge, ionizing radiation has
Chlorine, however, remains the predominant disin-
shown capabilities of reducing concentrations of
phenol and surfactants, increasing settling rates
fectant for portable water in the U.S. Although
ozone has had limited application in wastewater
and destroying chlorine in wastewater, and im-
proving physical characteristics of sludge. Engi-
treatment, equipment manufacturers and other
neers concerned with either upgrading existing
literature report many pilot studies have been
wastewater treating facilities or designing new
and are currently being conducted. Results indi-
facilities should be aware of this developing area
c a t e ozone is an effective disinfectant for
wastewater effluents. Use of ozone avoids the
of potentially applicable technology. Reference to
problems with aquatic life and disinfects at a
a v a i l a b l e literature or contact with HQDA
faster rate than chlorine. Ozone, however, is 10 to
(DAEN-ECE-G) WASH DC 20314, is suggested,
Authority to apply this emerging technology in
15 times as expensive as chlorine and on-site
any waste treatment process must be obtained
generation is necessary (80).
from DAEN-ECE-G.
(4) Hydrogen peroxide oxidation. Hydrogen
peroxide (H202) is a strong oxidizer but has only
d. Solids removal.
l i m i t e d application i n the disinfection of
moval.
wastewater. This is primarily because three to
(a) Description. Phosphorus removal is
four hours of contact time is required to accom-
needed because it is a major nutrient for algae
plish disinfection and it tends to leave a distinc-
and other aquatic vegetation. The sources of
tive taste. The primary use of hydrogen peroxides
phosphorus in a typical domestic wastewater for
is in industrial applications where it is extremely
a military facility are associated with human
effective in oxidizing a wide variety of pollutants.
excretions, waste foods and laundry products.
Uses include destruction of cyanide which is
While conventional wastewater treatment tech-
generated from electroplating and destruction of
niques, i.e., primary sedimentation and secondary
organic chemicals including chlorinated and sulfur
treatment, will remove about 10 to 40 percent of
containing compounds and phenols. Hydrogen
influent phosphorus, it often becomes necessary
peroxide is clear, colorless, water like in appear-
to provide for additional removal to meet effluent
ance and has a distinctive pungent odor. Hydro-
or water quality criteria. Numerous States in the
gen peroxide is not a hazardous substance and is
U.S. have developed water quality criteria and/or
considerably safer to handle and store than chlo-
effluent standards for phosphorus. Typical limita-
rine gas.
tions are 1 to 2 mg/L. However, recent standards
(5) Ultraviolet radiation. Ultraviolet radiation
being considered by regulatory agencies indicate
is a very effective alternative to chemical oxida-
levels for given situations may become more
tion. This method consists of exposure of a film
stringent. The U.S. EPA should be contacted for
of water up to several inches thick to quartz
requirements when wastewater treatment facili-
mercury-vapor arc lamps emitting germicidal ul-
ties alternatives include phosphorus removal.
traviolet radiation. This technique has been re-
ported to have been used on small systems in
for removing phosphorus have been identified,
Europe for over 100 years. Although this alterna-
6-17
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