Improved anaerobic digestion performances of whey in a batch reactor

Abstract: Biogas and methane yields, under different operating conditions, and chemical oxygen demand (COD) removal efficiencies were investigated in a mesophilic batch reactor (38°C)  for the mixtures of dairy manure (DM and cheese whey (CW  at 7% or 9% of total solids (TS . Biogas production of 401 L/kg of volatile solids (VS  and methane yield of 215.3 L/kg of VS was obtained after an operating time of 100 days for the mixture containing 7% of TS. A maximum increase in biogas production of 92% compared to the start-up phase was achieved with a volume of 3.6 L of biogas on day 55. The corresponding methane yield reached a maximum value of 80%.  The removal efficiency of the COD was 73%. Results show that anaerobic co-digestion of cheese whey and dairy manure with 7% of TS gives better results compared to 9% of TS.