Biogas Potentials for Anaerobic Co-Digested Rumen Contents and Sewage Sludge

Abstract

Sewage sludge (SS) and rumen contents (RC) are produced daily in waste stabilization ponds and abattoirs respectively as organic  wastes. However, these wastes could pose a threat to the environment if not properly managed hence, this research investigated the  potentials of these wastes in generating biogas. This was achieved by digesting different SS/RC ratios anaerobically for 30days and  recording the biogas produced under mesophilic condition. The SS and RC were obtained from Ahmadu Bello University (ABU) waste  stabilization pond and cattle (Bos indicus) respectively, while the SS/RC ratios considered were 1:0, 0:1, 1:1, 1:2 and 2:1. Results showed  that the co-digested organic wastes produced more biogas compared to mono-digestions of equivalent volumes of SS (1:0) and RC (0:1).  This is because the recorded daily biogas potentials for SS/RC ratios 1:0, 0:1, 1:1, 1:2 and 2:1 were 12.77, 19.59, 21.79, 23.85 and 20.45ml  per gram of TS added respectively. Hence, it was concluded that biogas potential for SS improved by 70.63%, 86.77% and 60.14% when co- digested with RC at SS/RC ratios 1:1, 1:2 and 2:1 respectively, while that of RC improved by 11.23%, 21.75% and 4.39% at SS/RC ratios 1:1,  1:2 and 2:1 respectively.