Produção de biogás a partir de resíduos de frigorífico de peixes

Abstract

Among the agroindustries of Paraná, there are fish slaughterhouses, which generate significant amounts of solid residues due to the process of meat processing. These residues have a high load of organic matter and nutrients that, if left untreated, cause contamination of the environment. One of the ways of treating waste is the anaerobic digestion that has as one of the products the biogas. The present study aimed to evaluate the biogas production potential from the solid waste generated in a fish slaughterhouse during the processing of the species Oreochromis niloticus, commonly known as Tilapia. To evaluate the biogas production, the tests were conducted in eudiometer. Tilapia residues were characterized by physical-chemical analysis of total solids (ST), fixed solids (FTS), volatile solids (VTS), total organic carbon (TOC), total nitrogen (NT), fat content, chemical Oxygen (COD), alkalinity and electrical conductivity. The biogas produced was also analyzed by the composition of methane, carbon dioxide, hydrogen sulfide and other gases, in a smaller quantity, by gas chromatography. As for the physicochemical characterization of the Tilapia residue, the pH at the beginning was maintained between 8 and 8.5, concentration of 34.17% of ST, 5.94% of STF and 28.23% of STV, carbon The total organic matter (TOC) was 20%, 1.9% of total nitrogen, 11.15% of fat, electrical conductivity of 11,63 μS.cm-1, and total alkalinity of 257 mg.L-1 of CaCO3. The carbon / nitrogen ratio presented 10.5: 1 necessitating the correction with vegetal residues to reach the ideal point. The initial COD of the obtained residue was of 2004.41 mgO2.L-1 obtaining an efficiency in the removal of 90%, and specific removal of the COD from the generated methane of 1.084,34 mLCH4.gDQO-1removed. The biogas production from the substrate waste was satisfactory, with a mean biogas production of 2.459 mLN.gSV-1, with an average content of 57.82% CH4, 6.65% N2-O2, 18.75% CO2, 0,0011% H2S and 7.47% H2O.