Alkaline Hydrolysis Application Procedures for Munitions Constituents Management Practices

Abstract

Department of defense (DoD) hand grenade training ranges have implemented alkaline hydrolysis, which is the practice of applying hydrated lime [Ca(OH)2] to range soil, to manage the deposition of Composition B components, such as hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX) and 2,4,6-trinitrotoluene (TNT). This paper will analyze hydrated lime effects on soil pH and the degradation of munitions constituents with time. At one DoD hand grenade training range, lime treatment produced higher soil pH values and RDX concentration reductions by eight orders of magnitude, some achieved concentrations in the low parts per trillion (ppt). The presence of calcite (CaO), a reaction product of Ca(OH)2, in field samples confirmed that alkaline hydrolysis reactions occurred in the soil matrix. In total, 5 months after the addition of lime to range soils, RDX was detected in collected field samples in small quantities. Column and lysimeter studies that use spiked native soils will be conducted to understand the effects of lime loading on RDX leachate and surface water runoff for site soils. The simulation efforts that used the training range environmental evaluation and characterization system (TREECS) modeling software predicted the reduction in aquifer RDX concentrations from the application of lime to the hand grenade range surface soil layer. The simulations verified the alkaline hydrolysis application parameters identified ex situ.