Laboratory simulation study of the solid-phase aerobic fermentation of nitrocellulose-containing wastewater sludge

The solid-phase aerobic degradation of nitrocellulose-containing sludge from the Aleksin Chemical Industrial Complex was studied by laboratory simulation with the use of activated indigenous microflora. This method applied to control physicochemical parameters (pH and aeration rate) led to an average nitrocellulose removal efficiency of about 26.3% during the first 9 days. The kinetic characteristics of the fermentation process were determined: the rate constants of nitrocellulose degradation varied from 0.026 to 0.036 day−1, and the half-life times were 20–27 days. Optimum operating conditions for nitrocellulose degradation by an indigenous microbial community were achieved at a sediment humidity level higher than 70%. Sodium humate was introduced into the test sludge as a rich source of organic materials in order to intensify the process of solid-state fermentation. Comparative analysis of the results revealed only an insignificant effect of physiological humate doses on nitrocellulose degradation. The maximum efficiency of nitrocellulose removal increased from 26.3% (base sample) to 29.4% upon the introduction of 1.6% sodium humate.