Simulated Rainfall-Driven Dissolution of TNT, Tritonal, Comp B and Octol Particles

Authors

Susan Taylor, Cold Regions Research and Engineering Laboratory, 72 Lyme Road, Hanover, NH
James H. Lever, Cold Regions Research and Engineering Laboratory, 72 Lyme Road, Hanover, NH
Jennifer Fadden, Cold Regions Research and Engineering Laboratory, 72 Lyme Road, Hanover, NH
Nancy Perron, Cold Regions Research and Engineering Laboratory, 72 Lyme Road, Hanover, NH
Bonnie Packer, US Army Environmental Command, Hoadley Road, Aberdeen Proving Ground, MD 21010, United States

Date of this Version

2009

Comments

Published in Chemosphere 75 (2009) 1074–1081.

Abstract

Live-fire military training can deposit millimeter-sized particles of high explosives (HE) on surface soils when rounds do not explode as intended. Rainfall-driven dissolution of the particles then begins a process whereby aqueous HE solutions can enter the soil and groundwater as contaminants. We dripped water onto individual particles of TNT, Tritonal, Comp B and Octol to simulate how surface-deposited HE particles might dissolve under the action of rainfall and to use the data to verify a model that predicts HE dissolution as a function of particle size, particle composition and rainfall rate. Particle masses ranged from 1.1 to 17 mg and drip rates corresponded to nominal rainfall rates of 6 and 12 mm h^-1. For the TNT and Tritonal particles, TNT solubility governed dissolution time scales, whereas the lower-solubility of RDX controlled the dissolution time of both RDX and TNT in Comp B. The large, low-solubility crystals of HMX slowed but did not control the dissolution of TNT in Octol. Predictions from a drop-impingement dissolution model agree well with dissolved-mass timeseries for TNT, Tritonal and Comp B, providing some confidence that the model will also work well when applied to the rainfall-driven, outdoor dissolution of these HE particles.