Resumen:
The objective of this research was to evaluate anaerobic co-digestion of guinea pig manure (GP) with Andean agricultural
residues such as amaranth (AM), quinoa (QU) and wheat (TR) in batch biodigesters under mesophilic conditions (37 0
C) for
40 days. As microbial inoculum, sewage treatment sludge was used in two inoculum/substrate ratios (ISR of 1 and 2). In terms of
methane production, the best results occurred in treatments containing AM and QU as co-substrate and an ISR of 2. Thus, the
highest methane production yield in the GP:AM biodigesters (25:75) and GP:QU (25:75) with 341.86 mlCH4/g VS added and
341.05 mlCH4/g VS added, respectively. On the other hand, the results showed that methane production with an ISR of 2
generated higher yields for guinea pig waste and the methane fraction of the biogas generated was in a range from 57 to 69%.
Methane production kinetics from these raw materials was studied using five kinetic models: modified Gompertz, logistic
equation, transfer, cone and Richards. The cone model adjusted best to the experimental values with those observed with r2 of
0.999 and RMSE of 1.16 mlCH4/g VS added. Finally, the highest biodegradability (experimental yield/theoretical yield) was
obtained in the GP-AM biodigesters (25:75) with 67.92%.
