Sanitary effectiveness and biogas yield by anaerobic co-digestion of swine carcasses and manure

Abstract

The present study evaluated anaerobic co-digestion of swine manure and swine carcasses for biogas yield and inactivation/behaviour of pathogens purpose. Biochemical Methane Production tests were performed with samples containing ratios of 3, 7.5 and 15 kg_carcass m^-3 _manure. For pathogens inactivation experiments known amounts of model microrganisms (sensitive and resistant) were artificially inoculated in anaerobic reactors at 24°C and 37°C. The addition of carcass resulted in an increase until 119% of biogas yield compared to swine manure mono-digestion. <i>Salmonella enterica</i>, <i>Escherichia coli</i> and PCV2 were reduced >3log₁₀ (24°C or 37°C) during 30 days. At 37°C, MS2 and PhiX-174 were reduced 3log₁₀ and 1.8log_10, respectively. At 24°C, MS2 reduced 1.5 log₁₀ and PhiX-174 did not present any decay over 30 days. Considering the most resistant biomarkers pathogens, as bacteriophage, we recommend the swine carcasses pre-treatment, such as high temperatures, for sanitary security.