The 6th International Conference on Biomass Energy (ICBE2018)

579 / 2018-11-10 12:53:54

Anaerobic co-digestion of urban sewage sludge with agricultural biomass

Plenary track > E.Gaseous Biofuel

Three different types of urban sewage sludges (the primarily mixed sludge, the dewatered secondary sludge and the sludge filtered by screens) were used for individual anaerobic digestion and co-digestion with agricultural biomass. It was found that the primarily mixed sludge exhibited prominent anaerobic digestion performance, selected as a potential reagent for the co-digestion with biomass. The total volume of the produced methane from co-digestion of the primarily mixed sludge and wheat stalk reached about 187 mL/g VSadded, which is about 1.52 times higher than that from the individual digestion of the sludge. the experimental value of methane yield from co-digestion of the primarily mixed sludge with wheat stalk is about 9.46% more than that of the estimated value, imply the enhanced interactions between the sludge and biomass during the co-digestion process. The pH of the co-digestion system of the primarily mixed sludge and wheat stalk was maintained at a relevant stable value around 6.50. This indicated that the buffering capacity of the biomass anaerobic digestion system can be improved with the addition of the primarily mixed sludge. The modified Gompertz model and first-order kinetic model were proposed to simulate the co-digestion process between the primarily mixed sludge and biomass straw. The estimated kinetic parameters indicated that the maximum releasing rate of methane was significantly increased during the co-digestion process.