Treatment of ammunition wastewater by the combined Fe0/air and Fenton process (1stFe0/air-Fenton-2ndFe0/air)

To mineralize the toxic refractory nitroaromatic pollutants in ammunition wastewater, the wastewater was treated by the combined Fe-0/air and Fenton process. Meanwhile, three control experiments, (a) Fenton, (b) Fenton intensified Fe-0/air and (c) combined Fe-0/N-2 and Fenton process, were set up to confirm the efficiency of the combined Fe-0/air and Fenton process. In addition, effects of initial pH, gas flow rate, Fe dosage, reactive time and hydrogen peroxide (H2O2) dosage on the treatment efficiency of the combined process were investigated, respectively. Under the optimal conditions, the results show that its COD was reduced from 518 to 28 mg/L, and BOD5/COD ratio was improved from 0.02 to 0.56. Furthermore, the analytical results of UV-Vis, excitation-emission matrix fluorescence spectrum (EEM) and gas chromatography mass spectrometry (GC-MS) suggest that all nitro-aromatic pollutants in the wastewater were removed completely. Therefore, all toxic refractory nitro-aromatic pollutants could be mineralized completely by the combined Fe-0/air and Fenton process. (C) 2016 Taiwan Institute of Chemical Engineers. Published by Elsevier B.V. All rights reserved.