Biochemical methane potential (BMP) from anaerobic co-digestion of sewage sludge and decanter cake

Abstract

Nowadays, anaerobic co-digestion has become a focus of interest in generating methane gas for electricity supply. In this study, a biochemical methane potential (BMP) test was conducted to determine biogas production potential from anaerobic co-digestion of sewage sludge and decanter cake. Sewage sludge has high organic content and decanter cake has a high carbon content (42.70%). Batch fermentation were performed in 125mL serum bottle with 100 mL working volume and incubated for 10 days at mesophilic temperature (38°C) in a water bath. Each bottle containing sewage sludge and decanter cake at feedstocks to inoculums (F/I) ratios of 1:0, 1:1 and 2:1. Daily biogas productions were collected using water displacement method. The highest cumulative biogas produces 0.25 L per day at the F/I ratio of 1:1. However, it was observed that the anaerobic co-digestion of sewage sludge with decanter cake at F/I ratio 2:1 provides higher methane yield production than that provided by the sewage sludge alone (1:0) and F/I ratio of 1:1. The results obtained revealed that the co-digestion of sewage sludge and decanter cake has a potential to produce methane.