Search

The objective of this research was to evaluate the anaerobic co-digestion of guinea pig manure (CY) with Andean agricultural residues such as amaranth (AM), quinoa (QU) and wheat (TR) in batch biodigesters under mesophilic conditions (37⁰C) 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 the treatments that contained AM and QU as co-substrate and an ISR of 2. Thus, the highest methane production occurred in the CY:AM biodigesters (25:75) and CY:QU (25:75) with 341.86 mlCH4/g VS and 341.05 mlCH4/g VS, respectively. On the other hand, the results showed that methane production with an ISR of 2 was more feasible for guinea pig waste, where the methane fraction of the biogas generated was in a range of 57 and 69%. The kinetics of methane production from these raw materials was studied using five kinetic models: modified Gompertz, logistic equation, transfer, cone, and Richards. The cone model was the one that best adjusted the experimental values ​​with those observed with an r2 of 0.999 and an RMSE of 1.16 mlCH4/g VS. Finally, the highest biodegradability was obtained in the CY-AM biodigesters (25:75) with 67.92%.

This study aims to evaluate the effects of the co‐digestion of agricultural residues with manure from camelids from the Andean zone. Different combinations of llama manure (LM) and vicuñas (VM) were made with amaranth (AS), quinoa (QS), and wheat (WS) residues. They were fermented using sewage sludge as inoculum. The co‐digestion was evaluated under mesophilic conditions for 40 days. The ratios of volatile substances of substrate / co‐substrate evaluated were 0:100; 25:75; 50:50, 75:25, and 100:0. Two substrate / inoculum ratios (SIR 1:1 and SIR1:2) were also evaluated. The results indicate that the maximum methane accumulation rate is obtained in SIR 1:1 for a VM‐AS ratio (25:75) with 540 mL/g volatile solid (VS). In general, the results did not increase with the increase in inoculum; rather, the tendency to improve methane yield is associated with an increase in the amount of agricultural residues, mainly AS. Regarding the kinetic modeling, the transfer model is the one that best adjusted the predicted values to those observed with an r2 between 0.991 and 0.999, and an RMSE value between 2.06 and 13.62 mL/g (volatile solid) VS. Finally, all the trials presented synergistic effects in their co‐digestion except the digesters formed by LM‐AS, LM‐QS and LM‐WS of SIR 1:2. These presented antagonistic effects in which the addition of the co‐substrate generated competition with the substrates, reducing methane production. © 2021 Society of Chemical Industry and John Wiley & Sons, Ltd

The objective of this research is to experimentally evaluate the anaerobic co-digestion of slaughterhouse residues in the city of Guaranda with straw residues from agriculture, such as: amaranth, quinoa and wheat. The study was carried out on a laboratory scale using 311 ml biodigesters under mesophilic conditions of 37 °C. Anaerobic co-digestion resulted in methane yields of 407 ml CH4/g VS, with a methane content in the biogas of 77% for the mixture of slaughterhouse waste and quinoa (RM-QU (25:75)). The increase in inoculum in the mixtures composed of slaughterhouse residues and quinoa increased the biodegradability between 17 and 22%. However, in the mixtures of slaughterhouse waste and amaranth (RM-AM (0:100)), a further increase in inoculum decreased biodegradability by 5%. To predict and simulate methane production, 5 kinetic models were used: modified Gompertz, logistic equation, transfer, cone and Richards. The cone model was the one that best adjusted the experimental values ​​with those predicted with an R2 of 0.982 to 0.999 and RMSE of 0.61 to 6.92 ml CH4/g VS. The calculation of the theoretical yield was carried out by stoichiometry and elemental analysis of the samples. Theoretical yields ranged between 480-564 ml CH4/g VS for all mixtures of RM with agricultural residues.

This paper evaluates the anaerobic digestion of agricultural waste, manure and slaughterhouse residues of species typical of the Andes, such as llama, vicuna and guinea pig; quinoa, amaranth and wheat straw in order to be able to use them as a renewable energy source and boost rural development in the region. Has been used sludge from a WWTP as inoculum, evaluating the effect of two relationships between the substrate and inoculum (RSI) for both livestock and agricultural waste. The highest cumulative maximum methane production rate was obtained for the residues of flame manure and quinoa straw for an RSI of 1:2 with productions of 376.08 ml CH4/g SV and 377.02 ml CH4/g SV respectively. In these materials an RSI of 1:2 obtained increases of 22.56% and 37.54% compared to the RSI 1:1. Also, the kinetic analysis showed that the modified Gompertz model is the one that best fits performance, with constant differences of 7.06% between the experimental and predicted values. On the other hand, the modified Gompertz model was adjusted to the experimental results with an r2 of (0.998) and an RMSE of 4.09 ml/g SV at 17.12 ml/g SV.

[EN] For the economically depressed communities such as of those in the Canton Guaranda, Ecuador, to generate their own energy, from organic waste is very important because they are sometimes insulated and its gas and electricity supply is very deficient. The aim of this research, was to determine the feasibility of anaerobic co-digestion of wasted cabbage from the town's market in Guaranda, Ecuador, and livestock manure. Two variables were studied: temperature of the process and the percentage of cabbage and livestock manure. Biogas quantity and kinetic parameters were evaluated. Kinetic model were analyzed by minimizing the mean percentage of error between the observed values (measured experimentally) and predicted, using the Runge-Kutta of order 4 for solving the system of differential equations obtained from mass balance. The results showed that a 50-50% ratio cabbage-manure at 30 degrees C temperature gave the highest production of biogas achieved is (389.47cm(3)N/g initial SV) with a composition of 61% methane. The kinetic parameters found were mu(max)=0.1053day(-1); Ks=0.1153mg/l; Y=0.00246g VSS /g COD and K-dec=0.001005day(-1)., This research work has been carried out inside the cooperation framework funded by the ADSIDEO program of the Centro de Cooperacion al Desarrollo (CCD) of Universidad Politecnica de Valencia (Spain), in collaboration with the Centro de Estudios de la Biomasa (CEB), Universidad Estatal de Bolivar, Guaranda, Ecuador. The participation of Dr. Sergio Perez in this work was possible thanks to funding from the Ecuadorian Government by means of the PROMETEO program, led by the Secretaria Nacional de Educacion Superior, Ciencia y Tecnologia (SENESCYT).