Impact of Thermal Pretreatment on the Physicochemical Characteristics and Biomethane Yield Potential of Solid Slaughter Waste from High-Throughput Red Meat Abattoirs Valorized as a Potential Feedstock for Biogas Production

Abstract

Rapid urbanization worldwide results in high demand for meat products, which in turn result in high numbers of animals being slaughtered for human consumption to meet food security demands, especially in low-income countries such as South Africa. The waste produced during slaughtering can serve as feedstock for biogas production. This study aims to determine the impacts of pasteurization and sterilization pre-treatments on high-throughput red meat abattoir solid slaughter waste’s physicochemical properties and biomethane yield when used as a feedstock for biogas production. Abattoir solid slaughter waste was collected from 45 high-throughput red meat abattoirs across South Africa and the various physicochemical properties were determined using standard methods, along with the impact of sterilization and pasteurization on red meat abattoir waste. Biomethane yield analysis was performed using AMPTS II with a hydraulic retention time of 40 days. Pasteurization and sterilization pretreatment was seen to increase physicochemical parameters such as pH, volatile solids, total solids, carbon, and nitrogen analyzed in all samples. Pasteurization and sterilization were also seen to increase biomethane yield, where methane production ranged from 610.67 Nml to 1756.30 Nml, 1592.20 Nml to 3319.30 Nml, and 949.57 Nml to 3297.87 Nml for untreated, sterilized, and pasteurized samples, respectively. There was no significant difference (p < 0.05) observed in the effect pasteurized and sterilized samples had on physicochemical properties and biomethane yield. It can be concluded that pasteurization and sterilization enhance the bioavailability of the physicochemical properties and biomethane yield of red meat solid slaughter waste when valorized as feedstock for biogas production.