Feasibility assessment of biogas production from the anaerobic co- digestion of cheese whey, grease interceptor waste and pulped food waste for WRRF

This study investigates the impact of co-digestion of waste activated sludge (WAS) and primary sludge (PS) with cheese whey (CW), grease interceptor (GI) waste, and pulped food waste (PFW) using lab-scale mesophilic anaerobic digesters (AD) and bench-scale biogas potential assays. The addition of CW (20% v/ v) and GI waste (10% v/v) with PS resulted in the increase of biogas productions (methane) by 15% and 2%, respectively compared to PS digestion only. The corresponding VS removal increased by 92% and 5% for CW and GI waste addition, respectively. Results from biogas potential assay experiments indicated that CW co-digestion with PS did not improve biogas productions but GI waste and PFW have the potential for improved biogas productions when mixed with PS. The experimental data were further used for detailed energy balance analysis of a water resource recovery facility (WRRF) to understand the influence of co-digestion on energy neutrality.(c) 2022 Elsevier Ltd. All rights reserved.

Automated summary

This study investigated the impact of co-digestion of waste activated sludge and primary sludge with various organic wastes on biogas production. The results showed that adding cheese whey and grease interceptor waste increased methane production by 15% and 2% respectively, and improved volatile solids removal. However, co-digestion of cheese whey and primary sludge did not enhance biogas production, whereas mixing grease interceptor waste and pulped food waste with primary sludge showed potential for improved biogas production. Additionally, detailed energy balance analysis of a water resource recovery facility was conducted to understand the influence of co-digestion on energy neutrality.