This paper investigates the reactivity of nanoscale iron particles (NIP) and lactate-modified NIP (LM-NIP) with 2,4-dinitrotoluene (2,4-DNT), a representative munitions contaminant, in kaolin and field sand as representative low and high permeability soils, respectively. Aluminum lactate, a green compound, was selected as the modifier based on earlier studies which showed it to be an effective dispersant for enhanced transport of NIP in soils. Kaolin and sand were spiked at concentration of 920 and 740 mg/kg of DNT. Batch experiments were conducted with NIP and LM-NIP dosages of 1, 4, 10, 20, 50, 75 and 100 g/L for 24 h. The effect of reaction time was then evaluated using NIP and LM-NIP dosages of 4 g/L for 1, 2, 4, 7, and 14 days. Higher NIP and LM-NIP dosages resulted in greater degradation of DNT in both soils. The DNT degradation ranged from 68% to 99% and 67% to 98% in kaolin and sand, respectively, with bare NIP, and it ranged from 65% to 99% and 59% to 98% in kaolin and sand, respectively with LM-NIP. The highest degradation was attained after 14 days in both soils. The reactivity of LM-NIP improved with time to levels as high as the reactivity of bare NIP. (C) 2010 Elsevier B.V. All rights reserved.