Treatment of military primary explosives wastewater containing lead styphnate (LS) and lead azide (LA) by mFe 0 -PS-O 3 process

Abstract

Abstract Lead styphnate (C6H3N3O9Pb, LS) and lead azide (Pb(N3)2, LA) are identified to be the only viable replacements for mercury fulminate and widely used in various industries. However, the treatment of military explosive wastewater containing these pollutants was rarely reported currently. On one hand, this kind of raw wastewater sample was hard to get and also difficult to treat, on the other hand, standard samples of main pollutants can not be found in the market, thus increased the difficulty of research. In this study, the treatment of wastewater containing lead styphnate and lead azide using mFe0-PS-O3 process was systemically investigated by single-factor experiments and control experiments. Then, the removal of major pollutants was analyzed by ultraviolet–visible spectroscopy and fourier transform infrared spectroscopy. Finally, the removal of Pb and Fe leaching during the treatment process were discussed in this study. The results show that lead styphnate and lead azide are easily removed by control processes, but the generated by-products during the treatment were hard to be further degraded. Comparing with them, mFe0-PS-O3 system was not only effective for the removal of main pollutants but also improved the degradation of intermediate products. Under the optimal conditions, chemical oxygen demand removal efficiency of 70.3% was obtained by mFe0-PS-O3 system, and the B/C ratio enhanced from 0.06 to 0.59. Collectively, these results suggest that mFe0-PS-O3 system should be proposed as an effective pretreatment process for the primary explosives wastewater.