Optimization of peroxone oxidation for removal of TNT from aqueous solutions using a process-intensified hydrogen peroxide dosing strategy

2,4,6,-Trinitrotoluene (TNT) is one of the most widely used explosives worldwide resulting in significant groundwater contamination. Peroxone is a dark oxidation process that uses the integrated reactions of ozone, hydrogen peroxide, and water to produce significant amounts of the hydroxyl radical, which is one of the most powerful oxidizers known. Peroxone was studied and optimized for TNT removal using a 30 min residence time, batch-fed hydrogen peroxide dosing strategy to yield an increase in process intensification. Results indicate that this intensified system was effective in TNT removal to below detection levels while producing and removing most of the produced 1,3,5,-Trintribenzene (TNB), a key by-product of incomplete oxidation. Up-front, batchadding hydrogen peroxide at 100 mg/l was deemed optimal, with doses above 1,000 mg/l performed worse than did ozonation alone. Testing at longer residence times eventually did show evidence of TNT degradation to fullmineralization, via complete nitrate liberation, or at least to low molecular weight organic aldehydes and carboxylic acids. Peroxone successfully treated the TNT contaminated influent.