Anaerobic codigestion of slaughter residues with agricultural waste of amaranth quinoa and wheat

Abstract

The objective of this research is to experimentally evaluate the anaerobic co-digestion of 16 slaughterhouse residues in the city of Guaranda with straw residues from agriculture, such as: 17 amaranth, quinoa and wheat. The study was carried out on a laboratory scale using 311 ml 18 biodigesters under mesophilic conditions of 37 °C. Anaerobic co-digestion resulted in methane 19 yields of 407 ml CH4/g VS, with a methane content in the biogas of 77% for the mixture of 20 slaughterhouse waste and quinoa (RM-QU (25:75)). The increase in inoculum in the mixtures 21 composed of slaughterhouse residues and quinoa increased the biodegradability between 17 and 22 22%. However, in the mixtures of slaughterhouse waste and amaranth (RM-AM (0:100)), a 23 further increase in inoculum decreased biodegradability by 5%. To predict and simulate methane 24 production, 5 kinetic models were used: modified Gompertz, logistic equation, transfer, cone and 25 Richards. The cone model was the one that best adjusted the experimental values with those predicted with an R2 26 of 0.982 to 0.999 and RMSE of 0.61 to 6.92 ml CH4/g VS. The calculation