Factors Affecting Color Development During
the Treatment of TNT Waste
MARSHALL W. NAY, JR., Assistant Professor
U.S. Air Force Academy
U.S. Air Force Academy, Colorado
CLIFFORD W. RANDALL, Associate Professor
PAUL H. KING, Professor
Virginia Polytechnic Institute and State University
Blackburg, Virginia
INTRODUCTION
Several investigations of the biodegradability and treatability of wastes from the TNT
manufacturing process were made during the 1940's and early 1950's (1,2,3,4). From the
results obtained, it was concluded that TNT waste was both toxic and refractory with
respect to biodegradation and that the possibility of biological treatment was marginal.
However, the wastes used in the previous studies cited, were obtained from the time
dependent batch manufacturing process, and contained high concentrations of so-called
"red water" complexes, which are considered to be the major cause of waste treatment
difficulties.
A recent innovation in TNT manufacturing has been the development of a counter-
current, continuous flow manufacturing process. In this process the raw materials are
continuously recycled during the nitration phases to make full use of their chemical
potential. In addition, prior to release of the resulting industrial waste, the red water
complexes developed during the nitration phases are separated from the waste flow and
destroyed by destructive distillation, resulting in a commercially marketable sodium sulfate
ash. The wastewater from the counter-current, continuous flow process is considerably
different from the batch process waste and is potentially more amenable to treatment. Thus,
this new manufacturing process appears to be more advantageous both economically and
ecologically.
The new counter-current, continuous flow manufacturing process was adopted by the
U.S. Army in 1968, after its service had been satisfactorily demonstrated in Europe and
Canada. The first munitions plant to begin utilizing this process was the Radford Army
Ammunition Plant located in southwest Virginia. Shortly after the plant was declared
operational, an extensive waste treatability project was begun in response to the many
Executive Orders resulting from the recent series of Water Pollution Control Laws. This
report summarizes the results obtained during the first stage of this study with particular
emphasis on color production.
WASTE CHARACTERIZATION
Waste from the continuous process contains four major waste components: excess
nitrobodies, spent acids, excess red water complexes, and cooling water. After production
start-up had begun the waste characteristics showed a large variance. On an average basis,
however, the waste flow characteristics may be summarized as shown in Table I.
Obviously, if the waste is to be treated biologically or discharged to a biological system,
the pH must be adjusted first. Unfortunately, it was found that an increase in pH by either
lime or soda ash neutralization greatly increased the color of the waste, with color values as
high as 6000 to 7000 standard color units resulting. Furthermore, biodegradation and
treatability studies showed that as the waste color increased, the waste became more toxic
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