Enhanced Efficiency for Biogas Production from Distillery Wastewater as Mixed with Molasses and Glycerol Waste in the Anaerobic Co-Digestion

Abstract

This experiment was conducted to decide the impact of molasses and glycerol waste on upgraded methane production in anaerobicco-digestion with distillery wastewater. Co-substrates used for biogas production in the anaerobic co-fermentation process ofdistillery wastewater (DW) were molasses (ML) and glycerol waste (GW). The co-substrate concentration in all batch experimentsvaried between 1% and 5% (v/v). To study the efficiency of biogas production, the optimal ratio was chosen for operation in thePFR continuous reactor. Optimization results indicated that anaerobic co-digestion of DW with 5% GW and 1% ML could improvebiogas quality and quantity. HRT for 30 days allowed R2 (95% DW: 5% GW) to produce maximum methane production per 11 m3CH4/m3mixed wastewater, followed by R1 (99% DW: 1%). ML) 6 m3CH4/m3mixed wastewater and control (100% DW) could onlyproduce 2.7 m3CH4/m3mixed wastewater methane. As co-substrates, GW and ML can be balanced to coordinate the C/N ratio andpH of DW. In particular, the C/N ratio of the mixed sewage can be balanced, and the concentration of ammonia nitrogen within ananaerobic digestion tank can be diluted. Therefore, GW can be used as an optimal co-substrate as it improves the C/N ratio, dilutestoxic compounds within DW, and provides lower prices, thus increasing the potential for methanogenesis within DW affected toincrease biogas production.