Abattoir Wastewater Treatment in Anaerobic Co-Digestion with Sugar Press Mud in Batch Reactor for Improved Biogas Yield

Abstract

Slaughterhouse wastewater (SHWW) has a great potential to generate biomethane energy when subjected to anaerobic digestion (AD). Nonetheless, the process is susceptible and prone to failure because of slow hydrolysis and the production of inhibitory compounds. Accordingly, to address this deficiency, anaerobic co-digestion (ACoD) is used to improve the treatment efficiency of the monodigestion of this high-strength waste and thereby increase methane production. The current investigation utilized the biochemical methane potential (BMP) test to assess the treatment performance of co-digested SHWW with sugar press mud (SPM) for improving biomethane energy recovery. It was established that the ACoD of SHWW with SPM increased methane (CH4) yield, enhanced organic matter removal efficiency and improved process stability, while also presenting synergistic effects. The anaerobic monodigestion (AMoD) of SHWW (100SHWW: 0SPM) showed a higher CH4 yield (348.40 CH4/g VS) compared with SPM (198.2 mL CH4/g VS). The 80% SPM: 20% SHWW mix ratio showed the optimum results with regard to organic matter removal efficiency (67%) and CH4 yield (478.40 mL CH4/g VS), with increments of 27% and 59% compared with AMoD of SHWW and SPM, respectively. However, it is also possible to achieve 5% and 46% CH4 yield increases under a 40% SPM: 60% SHWW mix proportion in comparison to the AMoD of SHWW and SPM, respectively. Furthermore, kinetic analysis of the study using a modified Gompertz model revealed that the CH4 production rate increased while the lag time decreased. The synergistic effects observed in this study demonstrate that incorporating SPM into the substrate ratios investigated can improve the AD of the SHWW. In fact, this represents the environmental and economic benefits of successfully implementing this alternative solution. Bioenergy recovery could also be used to supplement the country’s energy supply. This would help to increase the use of cleaner energy sources in electricity generation and heating applications, reducing the greenhouse gas effect.