Influence of heavy metals in the biomethanation of slaughterhouse waste

The results of two sets of experiments concerning the anaerobic digestion of Iberian pig slaughterhouse wastes are reported in the present work. In the first series experiments were carried out according to the actual proportions in which wastes were produced. In the second series of experiments, lung material was removed during the setup of the substrate, while the original proportions were maintained. The results highlight the influence of nickel on the biogas yield, Chemical Oxygen Demand (COD) degradation and economic viability of the process. Most notably, the use of substrate with lung waste led to a 21% decrease in biogas production rates. In addition, the lung waste substrate was found to increase the payback period for the construction of an anaerobic digestion plant of by 1 year when electrical energy generated by the anaerobic digestion plant is consumed in the slaughterhouse. However, no significant difference was found regarding the degree of substrate degradation.