CHARACTERIZATION AND TREATMENT OF EFFLUENTS FROM THE THREE MAIN STAGES OF NITROCELLULOSE PRODUCTION FOR EXPLOSIVES

L. F. Santos, F.T. Silva, T.C.B. Paiva

Abstract: This work shows the characterization of the effluents originating from the nitrocellulose industry and evaluates the combination of the chemical process with sludge activated for the treatment of these effluents. The delignification effluent presented color (24.166UC), TOC (20.850mg/L), COD (23.405mg/L) and BOD (5.865mg/L) very high. The bleaching effluent presented residual chlorine content of 14.2mg/L. The nitration effluent presented pH of 0.85 and acidity index of 1.02%, extremely low. These effluents presented toxicity to the bacteria Escherichia coli. The delignification effluent was submitted to the integration of processes: chemical followed by biological. The chemical treatment consisted in acidifying the effluent from the delignification stage at pH 1.2 to 1.8 with the nitration effluent, which is extremely acidic. This process allowed the coagulation/decanting of a large part of the organic materials present in the sample. The chemical treatment supernatant, after pH correction between 6.7 and 7.3, was submitted to biological treatment with activated sludge. To treat the bleaching effluent, a filtration system composed of a sand filter and an activated carbon filter was used. The treatment of the delignification effluent with the integrated process allowed reducing the color in 96.5%, the TOC in 98.2%, the COD in 98.7% and the BOD in 99.4%. The filtration system (sand filter and activated carbon filter) made it possible to reduce the chlorine content of the bleaching effluent by around 90%. Integrated treatment to treat delignification effluent; and physical, to treat the bleaching effluent, were effective for remediation of these effluents

Keywords: Effluents, Treatment, Cellulose, Lignin, Bleaching, E. coli

DOI: https://doi.org/10.15623/ijret.2017.0603008