4    OPPORTUNITIES FOR WASTE MINIMIZATION AT A
DRUM RECONDITIONING PLANT
Riley N. Kinman, Professor
University of Cincinnati
Cincinnati, Ohio 45219
David L. Nutini, Biologist
RNK Environmental, Inc.
Erlanger, Kentucky 41017
INTRODUCTION
The steel drum reconditioning industry in itself is a waste minimization operation since it has done
much to conserve steel and minimize the disposal of the used drums by recycling them. The steel drum
reconditioner must deal with a variety of liquid wastes in the processing of the steel drums. Wastes
may include motor oil, hydraulic oils, paints, varnishes, solvents, dyes, coating materials, detergents,
waxes, foodstuffs and even tomato paste drums.
This many materials makes this highly variable waste stream hard to deal with. This paper will
describe waste minimization methods and opportunities that arose after auditing a drum recondi-
tioner's operation and in the design of its wastewater pretreatment plant.
BACKGROUND OF DRUM RECYCLER'S OPERATION
A drum reconditioner handles about 350,000 drums per year. 205,000 of these are open head drums
and 145,000 are closed head drums. Therefore, the drum recycler uses two general processes to
recondition and recycle the 55 gallon steel drums. A flow plan of the open head process is shown in
Figure 1 and the closed head process is shown in Figure 2.
The open head process is a dry process except for cooling water from the exit end of the burner and
the residue that is dislodged when the drum is upended. Most of the wastewater comes from the closed
head washing process as noted in Figure 2.
The drum recycler washes a large percentage of motor oil drums as well as other materials as
mentioned above in the introduction. The process uses a hot 5% sodium hydroxide (NaOH) solution
to clean the material and residues from the drums. Labels are removed and dents are repaired.
Wastewater produced in the process contains a high pH, some oil and grease type materials, some
dissolved and suspended organics, elevated temperature and some metals in low concentration.
Wastewater quality is a function of the type of drum undergoing processing and, hence, may be highly
variable in solids, oil and grease, and metals. The pH is more often alkaline than acid and the
temperature is more often hot than cold. Composite samples of the sewered wastewater taken for
determining the design parameters of pretreatment plant are provided in Table I.
Some existing waste minimization techniques already existed at the drum reconditioning plant as
discovered during the audit of the facility. This included the following procedures: Caustic wastewater
from the washing area is recycled to a 10,000 gallon steel tank. Two oil-water separators remove the
oil and grease from the recycled caustic. The caustic is then returned to the wash tanks for reuse.
Recovered oil and grease are sent off-site for reclamation from two 5,000 gallon storage tanks on an
as recovered basis. Some caustic escapes the process with this oil and grease and a small quantity is
neutralized in the pH control of the final wastewater. Dry solids are sent off-site with the incinerator
ash and solids from the shot blasters. These materials are tested by TCLP procedures before transport
to a sanitary landfill for final disposal.
49th Purdue Industrial Waste Conference Proceedings, 1994 Lewis Publishers, Chelsea, Michigan 48118. Printed in
U.S.A.
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