EVALUATION OF AN AIR STRIPPING-OZONE CONTACTOR SYSTEM
J. J. McCarthy, Research Engineer
W. F. Cowen, Research Chemist
U.S. Army Medical Bioengineering Research
and Development Laboratory
Fort Detrick, Maryland 21701
E. S. K. Chian, Associate Professor
Department of Civil Engineering
University of Illinois
Urbana, Illinois 61801
INTRODUCTION
The latest generation of equipment for Army field hospitals derives from a building-
block concept called MUST:   Medical Unit, Self-contained, Transportable.   MUST-equipped
field hospitals are designed to be highly mobile centers of care capable of being deployed
anywhere in the world.
To ensure that the mobility of the MUST-equipped hospital is not impaired by the lack
of a safe and reliable water supply, a MUST Water Processing Element (WPE) is being developed.   The MUST WPE will have a nominal product water capacity of 3500 gallons per
day (gpd).   Operating in one configuration, it will renovate nonsanitary wastewaters generated by the hospital to a quality acceptable for nonpotable and eventually potable reuse.
Operating in a second configuration, it will simultaneously treat those same waters for
discharge to the environment while treating fresh or brackish natural waters for potable
and other uses.   Six nonsanitary wastewaters have been characterized from a MUST-equipped mobile field hospital.   These wastewaters are of industrial rather than municipal or
domestic nature.   Wastewater sources are operating room, kitchen, X-ray laboratory, clinical laboratory, shower and laundry [1].
Emphasis will be placed on the worst-case reuse operation.   The candidate unit processes
for the WPE reuse operation are, in sequence:   hydraulic equalization, 40-mesh screening,
ultrafiltration (UF), reverse osmosis (RO), ozone oxidation with ultraviolet (UV) light,
and hypochlorination.   Of the several unit processes proposed for the WPE reuse treatment
train, ozone oxidation is the least optimized and most controversial [2].   Pilot studies and
full-scale applications have demonstrated a certain potential for ozone oxidation or disinfection in domestic wastewater treatment plants [3].   Industrial applications for phenol
and cyanide reductions are operational [4].   Ozone oxidation of nonsanitary wastewaters
of the type expected from MUST-equipped Army hospitals is unique.
Initial efforts in the Army ozone program were presented by Reuter in 1973 [5].   By
that time the feasibility of ozone oxidation of selected MUST-type organic compounds
was shown and the necessity for incorporation of UV to aid in their removal was established.   Subsequent efforts ranged from detailed bench-scale parametric testing through
fabrication of pilot-scale equipment and detailed analysis of automatic control and instrumentation procedures.   These efforts are referenced in the next section.   This paper describes the results and efforts of a detailed in-house evaluation of a pilot-scale ozone contactor system built and designed for the US Army by Life Systems, Inc. of Cleveland,
Ohio.
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