ELECTROCHEMICAL TREATMENT OF TANK TRUCK WASH WATER
Gregory D. Reed, Assistant Professor
Civil Engineering Department
UMC/UMKC Coordinated Engineering Program
Kansas City, Missouri 64110
Louis Hemphill, Associate Professor
Civil Engineering Department
University of Missouri-Columbia
Columbia, Missouri 65211
INTRODUCTION
The purpose of this presentation is to examine some of the concepts relative to electrochemical methods of waste treatment and to evaluate the on-stream performance of a
proprietary electrochemical waste treatment system. To facilitate an understanding of the
potential advantages of electrochemical treatment of strong waste waters, tank truck wash
water has been selected as an example of a difficult treatment problem.
The mobility of trucking has produced a significant level of transport of industrial liquids
of all types by tanker. These tank trucks are cleaned and reused for a variety of products.
It is estimated that wastewater in excess of 50 million gallons per year is produced by these
washing operations. Typical strength values are shown in Table 1. The high variability of the
waste presents the most significant problem. This variation can occur during the daily operation of the facility as well as over a period of several days. In addition, as many as 47
different chemicals have been identified at a single station.
CONVENTIONAL SYSTEMS
The application of conventional treatment systems has proven to be complex and expensive. For example, Figue 1 shows the flow diagram of a system developed under a joint
venture of the U.S. Environmental Protection Agency and Matlock Corporation [ 1 ]. The
treatment system consists of gravity oil separation, pH adjustment, cationic and anionic floc-
culant addition, air flotation, multi-media filtration, carbon adsorption, and rotating
biofiltration units. The cost of the faciltiy was set at $50/1000 gallons treated, with the cost
breakdown shown in Table II.
At this point it becomes obvious that the use of conventional systems will be a very
expensive proposition. Is there a better way?
ELECTROCHEMICAL TREATMENT
Electrochemical treatment of organic wastes is a persistent idea which probably
originated about 1880.   Curiously, there are a number of U.S patents which describe in
rather glowing terms the unique action and potential benefits afforded by electrochemical
treatment of wastewater [2]. The patent literature includes a generous offering of ingenious
schemes and devices that range from simple D.C. electrolysis to complicated plasm arc devices. Some of the published .patents include a comprehensive resume of operation together
with pilot plant performance data. This feature suggests that the basic idea of electrochemical treatment are functional and that application is practical.
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