The economic efficiency of the co-digestion at WWTPs: A full-scale study

The methane and digestate production from biowaste (BW, 95% food waste 5% garden based on fresh mass) grease trap sludge (GTS) co-digestion at the Grossache-Nord WWTP (Austria) as a basis for cost-benefit analysis was determined using two approaches: first one to determine specific yields (SMY) total solids (TS) removals (%) of used substrates in biomethane potential (BMP) tests. In second, full-scale process data supervisory control acquisition (SCADA) system were analyzed. From these data, SMY sewage (SS) calculated period without applied study period. Thus, it possible calculate co-substrates. Both approaches produced different co-substrate SMYs TS degradation results. approach BMP, 518 m3/t TSadded 77%. For method, values found be 620 66%, respectively. However, both indicated that electricity generation can cover associated costs. benefit cost ratio 1.14 1.08 BMP approach, application respective depends availability quality SCADA data.