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Abstract: Millions of tons of nitroaromatic explosives are produced worldwide for military purposes and other applications. These substances lead to the accidental release of energetic materials, resulting in soil and groundwater pollution. Nitroaromatics are easily reducible because of their polarized N–O bands. Therefore, they are not sorbed strongly in the environment due to the intermediate character between hydrophobic and hydrophilic properties. Advanced oxidation processes (AOPs) have recently been used to degrade emerging pollutants due to generating highly oxidizing agents, such as hydroxyl radical. The main objective of this study is to examine the possibility of the persulfate/ozone (as an activator) process in explosive degradation from an aqueous solution. Experiment designs and data analysis were evaluated using the Taguchi design method considering COD and TOC removal as responses. Next, 2,4,6-trinitrotoluene (TNT) residual concentration was detected using the HPLC instrument. Finally, the most significant parameters that affected response removal were determined by variance (ANOVA) analysis. A satisfactory agreement of the quadratic model with the experimental data was confirmed by the high R2value (close to 1). The correlation coefficient of 0.9 indicates the high validity of the obtained models for removing COD and TOC. Hence, in removing COD and TOC, a very good agreement was found between the experimental values and the predicted values of the responses. Two-third of 2,4,6-trinitrotoluene was transferred to inorganic compounds corresponding to CO2due to the generation of oxidative species. More than 72% COD and 65% TOC removal efficiency were obtained in 60 min employing pH neutral, PS 19 mM, and 40 mg/L TNT (kt= 0.0191 min–1, pseudo-first-order kinetic model). Overall, sulfate radicals activated by ozone could be considered a promising process for nitroaromatic degradation of industrial effluent.

Energetic compounds are widely used in various activities, including military exercises and conflicts. Researchers recently proved that these compounds could persuade apoptosis through DNA damage, endoplasmic reticulum stress, and mitochondrial dysfunction in Hep3B and HepG2 cells. This study investigated the possibility of potassium ferrate as an eco-friendly and simultaneous activator (PS/PF/O3) for explosive degradation from an aqueous solution. Taguchi design method was used for evaluating the effect of different operational parameters. chemical oxygen demand (COD) and total organic carbon (TOC) removals were considered responses of the study experiments by analysis of variance (ANOVA). The optimum condition was achieved at neutral pH value and an oxidant dose of 19 mM; 40 mg/L of 2,4,6-trinitrotoluene within 60 min responded to almost 89.3% of COD and 75.7% of TOC removal by PS/PF/O3process. In the mentioned condition, 2,4,6-trinitrobenzaldehyde, 2,4,6-trinitrobenzoic acid, and 1,3,5-trinitrobenzene were the main intermediates detected by liquid chromatography–mass spectrometry analysis. Also, this reaction chain was subsequently continued, and nitrate ions were identified as a key factor for mineralization. Bioassay test also demonstrated a considerable reduction in toxicity after each process. The dispersion test of Daphnia magnaassay on treated red-water ranked as follows: stock solution (high toxicity) >> PF/O3effluent > PS/PF/O3(low toxicity). Degradation of 2,4,6-trinitrotoluene was in accordance with the pseudo-first-order kinetic model (R2= 0.98). It can be concluded that potassium ferrate makes the PS/O3process a reliable technique for explosive mineralization (as a green iron-based activator).