高大毛壳对硝化纤维素的降氮机理

In view of the serious potential safety problems of waste propellants, five microorganisms that can reduce the nitrogen content of nitrocellulose (NC) are obtained by sampling, enriching, domesticating, separating and purificating near and around the wastewater treatment tank of nitrocellulose production. The time optimization experiment was carried out on the chaetomium elatum which has the best denitrification effect among them. It is found that the nitrogen content of NC could be reduced from 13.06% to 10.83% over time, and the X-ray photoelectron spectroscopy (XPS) results show that the content of N element on the surface of NC gradually decreases. Fourier Transform infrared spectroscopy (FT-IR), inVia Raman microscope (Raman) and gel permeation chromatography (GPC) are used to characterize the structure and molecular weight of NC. The infrared spectrum shows that the —OH peak intensity of NC at about 3 400 cm ^-1 is gradually increased because the hydrolysis of chaetomium elatum and O—NO₂ occurs and the Raman spectrum shows that the intensity of NC energetic groups (O—NO₂) decreases significantly. At the same time, it is found by GPC that the number-average molecular weight and weight-average molecular weight of NC could be reduced by 2.34% and 6.40%, respectively, due to chaetomium elatum. In order to further determine the biological enzymes acting on NC, the separation of extracellular enzymes and intracellular enzymes, and ammonium sulfate gradient precipitation experiments proved that the extracellular enzymes precipitated by 0-30% (NH₄) ₂ SO₄ could effectively reduce the nitrogen content of NC. The significant effect of chaetomium elatum on reducing the nitrogen content of NC makes it have broad application prospects in the reuse of waste military NC and the biological denitrification of propellants.