title: Mobility of 2-amino-4,6-dinitrobenzoic acid, a photodegradation product of TNT in a tropical soil under saturated abiotic conditions.
abstract: We examined the mobility of 2-amino-4,6-dinitrobenzoic acid (2-A-4,6-DBA) a common photodegradation product of TNT, in soil taken from a former military training area on Oahu Island, Hawaii, USA. 2-A-4,6-DBA is stable and polar and has the potential to migrate to groundwater. Little experimentation has been conducted on explosives in tropical soils which differ chemically from soils in temperate climates. 2,4,6-Trinitrotoluene (TNT) and 1,3,5-hexahydro-1,3,5-trinitrotriazine (RDX) are the most commonly used secondary military explosives. Composition B (Comp B) is a frequently used 59/40/1 combination of RDX, TNT, and wax binder. In order to examine the effect of the presence of Comp B and its degradation products on the mobility of 2-A-4,6-DBA in soil, we dissolved field-collected Comp B fragments in water, exposed the solution to light and pumped it through soil and sand-packed stainless steel columns under abiotic saturated conditions. We found that in the presence of a complex mixture of explosives and degradation products, 2-A-4,6-DBA migrated faster than the parent compound (TNT) and other degradation products through both tropical soil and Ottawa sand (used as a reference) under sterile saturated conditions. The relatively rapid movement of 2-A-4,6-DBA suggests that it has the potential to contaminate underlying groundwater. However, the amount of 2-A-4,6-DBA produced under field conditions and its rate of biotic degradation were not part of this research, therefore, it is unknown how these factors might affect the transport and fate of 2-A-4,6-DBA.
authors.affiliation: Applied Research Lab at the University of Hawaii, 2800 Woodlawn Drive, Room 170, Honolulu, HI 96822, United States.
authors.forename: Lukas D
authors.initials: LD
authors.lastname: Sheild
authors.forename: Joseph
authors.initials: J
authors.lastname: Lichwa
authors.forename: Edwin J
authors.initials: EJ
authors.lastname: Colon
authors.forename: Philip
authors.initials: P
authors.lastname: Moravcik
authors.forename: Chittaranjan
authors.initials: C
authors.lastname: Ray
mesh_terms: D000327:Adsorption; D000538:Aluminum Silicates; D001673:Biodegradation, Environmental; D002851:Chromatography, High Pressure Liquid; D000077215:Clay; D053834:Explosive Agents; D006254:Hawaii; D006863:Hydrogen-Ion Concentration; D008027:Light; D009579:Nitrobenzoates / Q000737:chemistry*; D010782:Photolysis; D012987:Soil; D012989:Soil Pollutants / Q000737:chemistry; D013696:Temperature; D014303:Trinitrotoluene / Q000737:chemistry*; D014867:Water / Q000737:chemistry; D014874:Water Pollutants, Chemical / Q000032:analysis*; D014887:Weather; D062367:ortho-Aminobenzoates / Q000737:chemistry*
chemical_list: D000538:Aluminum Silicates; D053834:Explosive Agents; D009579:Nitrobenzoates; D012987:Soil; D012989:Soil Pollutants; D014874:Water Pollutants, Chemical; D062367:ortho-Aminobenzoates; D014867:Water; D014303:Trinitrotoluene; C587445:2-amino-4,6-dinitrobenzoic acid; D000077215:Clay
keywords: 2-Amino-4,6-dinitrobenzoic acid; Photodegradation; RDX; TNT; Tropical soil