Advanced Oxidation Process for DNAN Using UV/H₂O₂

2,4-Dinitroanisole (DNAN) is an important component of insensitive munitions that is anticipated to replace 2,4,6-trinitrotoluene (TNT) in munitions formulations. Photocatalyzed hydrogen peroxide (H₂O₂) oxidation experiments and chemical analyses were conducted to study the effect of initial pH and H₂O₂ dosage on the kinetics of DNAN decomposition and the reaction pathways. The results show that DNAN degradation followed zero-order kinetics when a 250 ppm DNAN solution was treated with ultraviolet (UV) light and 1500–4500 ppm H₂O₂ in an initial pH range of 4–7. However, when the H₂O₂ concentration was 750 ppm, DNAN degradation followed pseudo-first-order kinetics. The results indicate that DNAN can easily be oxidized by UV/H₂O₂ treatment. When the H₂O₂ dosage was 1500 ppm and the initial pH was 7, DNAN was reduced from 250 ppm to less than 1 ppm in 3 h. However, the total organic carbon (TOC) and total carbon (TC) concentrations were reduced slowly from 100 to less than 70 ppm carbon (C) in 3 h, and decreased to about 5 ppm after 9 h of treatment, suggesting the formation of other organic compounds. Those reaction intermediates were oxidized to carbon dioxide (CO₂) at a slower rate than the oxidation of DNAN. CO₂ was emitted from the solution because the solution pH decreased rapidly to about 3 during the UV/H₂O₂ oxidation. Most of the nitrogen in DNAN was converted to nitrate by UV/H₂O₂ oxidation after 9 h of treatment. The research results indicate that UV/H₂O₂ oxidation is a promising technique for the treatment of DNAN in wastewater.