The treatment of a munitions manufacturing waste with lime, chlorine and permanganate

Abstract

Lime, chlorine, and potassium permanganate have long been important chemicals in the treatment of municipal and industrial wastewater. Their effectiveness in treating munitions manufacturing wastes was determined in a laboratory study using bench scale coagulation tests designed to simulate the facilities presently used to treat the wastewater. The wastewater from the new counter-current flow TNT manufacturing process at the Radford Army Arsenal Plant, Radford, Virginia, was found to be treatable by excess lime addition alone or in combination with the oxidants chlorine and potassium permanganate. The excess lime treatment removed 86 percent of the Silas-Mason reactable substances but created a color problem. The oxidants were employed to remove the color developed by the lime addition. Optimum color removal occurred if the chlorine was added to the waste at pH 6. The potassium permanganate treatment system was limited by the color imparted to the waste and by the slow reaction of the permanganate with the organic compounds in the presence of lime. Optimum color and TNT removal was obtained by adding the potassium permanganate at pH 2. A TNT removal of 81 percent was obtainable with a permanganate concentration of 50 mg./l. followed by excess lime treatment. Zinc sulfate addition marginally improved system performance.