Biochemical Methane Potential of Slaughterhouse Organic Waste Co-Digestion: A case study in Arequipa-Peru using Augmented Simplex-Centroid Method

Abstract

The meat industry has been growing steadily and significantly in recent decades on a global scale. This boom has intensified the challenges associated with waste management, especially due to the generation of organic waste from slaughterhouses, which poses an environmental risk when not properly managed. In this context, the present study aimed to analyze biogas production through the anaerobic co-digestion of blood (SA), manure (ES), and ruminal content (CR) in a case study, a slaughterhouse in the Arequipa region of Peru. To this end, biochemical methane potential (BMP) tests were carried out using an augmented simplex-centroid experimental design. The substrates were characterized physicochemically and subjected to triplicate tests under controlled conditions (35 °C), applying the GD BMP method to quantify the biogas produced every three days. Statistical analysis (ANOVA) showed significant differences between the formulations (p < 0.05). The mixture composed of 66.67% blood achieved the highest yield among the formulations (704.34 ml biogas/g DM), while the monodigestion of blood presented the highest average value (725.60 ml biogas/g DM). Intermediate values showed moderate yields (339-472 ml biogas/g DM), while treatments with a predominance of ES and CR recorded lower values, with pure manure standing out at 153.8 ml biogas/g DM. The results demonstrated the positive effect of blood as a highly biodegradable substrate and the limitation of fibrous materials, confirming the relevance of co-digestion as a recovery solution in optimizing biogas production from organic waste generated in slaughterhouses.