These reactions are called synergistic effects. To evaluate the influence of each substrate in the different mixtures and calculate the possible synergistic effects that could be produced during the biodegradation process the subsequent Eq. (11) was used: equation(11) α=Experimental productionTheoretical productionThe

“experimental production” is the result of the BMP tests for each co-digestion mixture while the “theoretical production” is the theoretical value obtained from the Bioactive Compound Library solubility dmso BMP of the sole substrates considering the VS of each substrate contained in the final mixture. The result of α indicates: – α > 1; the mixture has a synergistic effect in the final production. The experimental results were obtained after a period of 39 days when the BMP assays ended with a dairy production of less than 1%: Fig. 1 shows the productivity during all the experiment for the sole substrates (OFMSW and biological sludge) and its co-digestion mixtures. The standard deviation calculated from the results of the triplicates is also represented showing the consistency find more of the experiments. Similar final productivities were obtained for all the co-digestions of biological sludge and OFMSW. Co-digestion

1 obtained the best productivity values (221 mlCH4/gVS) for the BMP tests followed by the next co-digestion configurations 2 and 3 with 217 mlCH4/gVS and 212 mlCH4/gVS respectively. All these mixtures obtained higher values than the sole substrates OFMSW and biological sludge, while co-digestion 4 just achieved a 22% increase from the biological sludge production as sole substrate. Methocarbamol Although biological sludge achieves the lowest production, the methane content is higher than in both OFMSW and the co-digestions, obtaining values of over 60% for methane composition from the third day while the other substrates did not achieve 60% methane during the whole experiment. One of the objectives of this work is to find the optimum mixture for the co-digestion of biological sludge and OFMSW, which will

be the co-digestion that increases its productivity from both sole substrates (OFMSW and biological sludge) to the maximum. Co-digestions 1, 2 and 3 increase the productivity of OFMSW and biological sludge, even though co-digestion 1 achieve the best results with an increase of 9% for OFMSW and 34% for biological sludge. Then we can confirm that the configuration used for co-digestion 1 (80% OFMSW and 20% biological sludge) is the optimum, however all the co-digestion mixtures achieve productivities over the sole substrates indicating that the co-digestion of OFMSW and biological sludge could be a good opportunity to enhance both substrates. The ability of the theoretical methodologies to accurately estimate methane yields of complex substrates was evaluated by comparing the experimental productivity from the BMP tests with the theoretical productivity obtained from the different methodologies.