Lime Treatment of Explosives-Contaminated Soil from Munitions Plants and Firing Ranges

Abstract

Microcosms were prepared using soils from munitions plants and active firing ranges and treated with hydrated lime. The presence of particulate explosives and co-contaminants, and the concentration of soil total organic carbon (TOC) on the alkaline hydrolysis reaction were studied. Trinitrobenzene (TNB) and dinitrobenzene (DNB) were sensitive to alkaline hydrolysis under these experimental conditions. The TNT metabolites, 2A- and 4A-DNT, were also removed, although more slowly than the parent compound, and the reaction required a higher pH (>12). RDX retention in the soil was proportional to the TOC content. The degradation intermediates of the alkaline hydrolysis reaction partitioned in the soil matrix in a manner similar to the parent. Solid particles of explosives are also degraded by alkaline hydrolysis. RDX and HMX exhibited 74 and 57% removal, respectively, in 21 days. TNT, as whole and broken grains, showed 83 and 99.9% removal in 21 days, respectively. The propellants, 2,4- and 2,6-DNT, were insensitive to alkaline hydrolysis. Alkaline hydrolysis is an inexpensive and effective means of reducing the varied explosives contamination.