Effective microorganisms delignification of empty fruit bunch as co-substrate in palm oil mill effluent anaerobic digestion

The Anaerobic Co-Digestion (ACD) of POME and EFB is widely applied to produce biogas by converting Chemical Oxygen Demand (COD). However, the lignin content in the EFB hinders the performance of the anaerobic bacteria. Therefore, this paper proposes EFB delignification by effective microorganisms (EM). Shredded EFB was delignified using EM solutions of 1.96%, 3.85%, and 5.66% v/v (EMD196, EMD385, EMD566). Five Erlenmeyer flasks were mesophilic anaerobic digesters for 21 days. The first two acted as controls, with and without co-substrate (CTRL1 and CTRL2). Another three co-digested by adding the delignified EFB. Compared to CTRL1, EMD566 showed the highest increase in performance, with a gain in cumulative biogas production at 137.21% and methane content at 4,328%. EMD566’s reduction of COD and total solids (TS) improved by 25.09 and 4.98%. It can be concluded that EMD566 is the most promising in enhancing biogas production.