&EPA
                                  .United States
                                  Environmental Protection
                                  Agency
                EPA/540/MR-93/520
                August 1993
                                  SUPERFUND  INNOVATIVE
                                  TECHNOLOGY EVALUATION
                                  Demonstration  Bulletin

                            CAV-OX® Ultraviolet Oxidation Process
                                    Magnum Water Technology
Technology Description: The CAV-OX® technology (see Fig-
ure 1) destroys organic contaminants, including chlorinated hy-
drocarbons, in water. The process uses hydrogen peroxide, hy-
drodynamic cavitation, and ultraviolet (UV) radiation to photolyze
and oxidize organic compounds present in water at part  per
million to nondetectable levels. Ideally, the end products of the
process are water, carbon dioxide, halides, and in some cases,
organic acids. The major components of each CAV-OX® system
are the cavitation chamber, UV reactor, and control panel unit.

Cavitation occurs when a liquid undergoes a dynamic pressure
reduction while under constant temperature. The pressure reduc-
tion causes gas bubbles  to suddenly develop, grow, and then
collapse. Cavitation decomposes water into extremely reactive
hydrogen atoms and hydroxyl radicals, which recombine to form
hydrogen peroxide and molecular hydrogen.

The CAV-OX® technology induces hydrodynamic  cavitation
through the shape of its cavitation chamber, which causes pres-
sure variations in a flowing liquid. The cavitation process gener-
ates hydroxyl radicals and hydrogen  atoms, which recombine to
              Groundwater from
           Site 16 Monitoring Wells
form hydrogen peroxide and molecular hydrogen. Flow can be
recycled through the cavitation chamber to control the hydraulic
retention time before it is transferred to the UV reactor.

The UV reactor houses low-pressure mercury-vapor lamps that
generate UV radiation, which further oxidizes the organic com-
pounds. Each lamp is housed in a UV-transmissive quartz tube,
which is mounted  entirely within the UV  reactor.  Hydroxyl and
hydroperoxyl radicals are produced by direct photolysis of hydro-
gen peroxide at UV wavelengths.

Magnum Water Technology manufactures both  low-energy and
high-energy UV systems. The low-energy CAV-OX® I system
contains six 60-watt lamps per reactor. The  high-energy CAV-
OX® II system contains two UV reactors with one UV lamp each
and can operate  at 2.5, 5,  7.5,  or  10  kilowatts (kW). Flow
capacity is estimated to be less than 3 gals per minute (gpm) for
the low-energy system and less than 5 gpm for the high-energy
system as demonstrated. Three configurations of the CAV-OX®
technology were demonstrated: the CAV-OX® I system operating
at 3(50 watts and the CAV-OX® II system operating at both 5 kW
andlOkW.
                                                                       Low-Energy
                                                                       UV Reactor
                                                                                          _^.  To Effluent
                                                                                        ™"    Storage Tank
Figure 1.  The CAV-OX* Technology as Demonstrated
              High-Energy
              UV Reactor
                                                                                         Printed on Recycled Paper

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Demonstration Approach: The CAV-OX® technology was dem-
onstrated at Edwards Air Force Base Site 16 for 2 weeks in March
1993, Almost 8,500 gals of contaminated groundwater from Site
16 monitoring wells were treated during this period. Groundwater
at Site 16 is contaminated with volatile organic compounds (VOCs),
primarily trichloroethene  (TOE)  and  benzene, toluene,
Qthyibenzene, and xylenes (BTEX).

During the demonstration, groundwater was pumped from three
Sits 16 monitoring wells into a 7,500-gallon equalization tank. A
bladder tank was  used  as the equalization  tank to minimize
variability in influent characteristics. Influent contaminant concen-
trations included 1,475 to 2,000 parts per billion (ppb) TCE, 240 to
500 ppb benzene, 8 to 11 ppb toluene, and 0 to 100 ppb xylene.
From  the equalization tank, the water was transfered to an influ-
ent holding tank, where hydrogen peroxide was added. The water
was then pumped to the cavftatfon chamber followed by either the
high-energy or tow-energy UV reactor. Treated groundwater was
stored in an effluent storage tank prior to disposal.

Tha demonstration consisted of 15 runs for each configuration of
the CAV-OX® technology. The high-energy system was first oper-
ated with the UV reactor at 10 kW and then at 5 kW. Groundwater
samples were collected before and after treatment during each
run to determine the technology's effectiveness in removing VOCs
from groundwater.

The principal operating parameters — hydrogen peroxide dose,
pH, and  ffow rate  — were varied during the demonstration  to
  iluata the technology's  performance under different conditions.

 ibti 1. Summary of preliminary demonstration Results - CAV-OX9 Systems
                                                         Preferred operating conditions? those under which the concentra-
                                                         tions of effluent VOCs were reduced below target levels at the
                                                         least cost, were used for the last three runs for  each configura-
                                                         tion.  Specific VOC levels and chemical constituents were also
                                                         monitored.

                                                         Preliminary Results: The CAV-OX® I and CAV-OX® II systems
                                                         achieved removal efficiencies of up to >99.9 percent for TCE and
                                                         BTEX compounds. No scaling of the quartz tubes was observed.
                                                         Preliminary results from the demonstration for the CAV-OX®
                                                         systems are shown in Table 1.

                                                         Key findings from the demonstration, including complete analyti-
                                                         cal results and economic analysis, will be published in an Appli-
                                                         cations Analysis Report and a Technology Evaluation  Report.
                                                         These reports will be used to evaluate the CAV-OX® technology
                                                         as an alternative for cleaning up similar sites across the country.
                                                         Results will also be presented in a project summary report and a
                                                         videotape.

                                                         For Further Information:

                                                         EPA Project Manager:

                                                         Richard G. Eilers
                                                         U.S.  Environmental Protection Agency
                                                         Office of Research and Development
                                                         Risk Reduction Engineering Laboratory
                                                         26 West Martin Luther King Drive
                                                         Cincinnati, OH 45268
                                                         (513) 569-7809
1 if wi **£! w" '
Pofoxfao
Tsrset
Levels Rolv
(mgfL) gpm
30
30
30
60
60
60
90
90
SO
0
0
0.5
0.6
1.5
0.6
0.7
1.5
0.5
0.7
1.5
—
—

CAV-OX11 1




Removal Efficiencies (%)
TCE

99.9
99.9
71.4
99.7
87.8
61.7
96.4
87.1
58.6
_
—
Benzene

>99.9
>99.9
88.6
>99.9
96.9
81.6
99.4
96.5
86.1
—
—
Tolune

99.4
>99.9
87.4
>99.9
94.5
83.8
99.8
97.6
87.3
—
—
Xylene Flow
gpm
92.9
>99.9
65.6
>99.9
92.1
80.2
98.9
98.1
>99.9
—
1.5
2.0
4.0
1.4
1.9
3.9
1.4
1.9
4.0
1.6
— 1.8
TCE
5-kW
99.6
99.7
87.7
99.8
98.4
85.1
99.6
97.8
86.3
94.1
80.6
10-kW
99.2
99.7
98.1
99.7
99.3
97.1
99.4
99.2
98.9
99.2
97.6
CAV-OX* 1
Removal Efficiencies (%)
Benzene Tolune
5-kW 10-kW 5-kW 10-kW
99.4 98.8 >99.9 98.6
99.5 99.6 >99.9 >99.9
89.7 98.7 88.8 97.1
99.8 99.8 >99.9 >99.9
98.8 99.3 96.9 98.6
89.5 97.8 91.8 97.9
99.6 99.6 99.8 99.8
99.4 99.5 99.5 99.7
93.5 99.5 94.5 99.6
49.1 68.1 20.7 54.7
38.5 60.5 48.6 75.2




Xylene
5-kW 10-kW
>99.9
>99.9
78.7
98.7
93.6
90.4
99.5
99.2
95.4
43.3
56.9
>99.9
>99.9
87.2
>99.9
97.0
96.0
99.5
99.7
>99.9
46.7
83.8
 * milligrams por Star

United States
Environmental Protection Agency
Center for Environmental Research Information
Cincinnati, OH 45268

Official Business
Penalty for Private Use
$300
                                                                                   •U.S. Government Printing Office: 1993 — 750-071/80046
                                                                                              BULK RATE
                                                                                        POSTAGE & FEES PAID
                                                                                                  EPA
                                                                                           PERMIT No. G-35
    EPA/54Q/MR-93/520

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