title: Addition of crude glycerine as strategy to balance the C/N ratio on sewage sludge thermophilic and mesophilic anaerobic co-digestion.
abstract: The effect of adding crude glycerine during continuous sewage sludge anaerobic digestion was investigated under thermophilic and mesophilic temperatures. Addition of CGY at thermophilic temperature range showed a negative impact on stability and performance of the process, even at low doses. The extreme pH values of CGY, together with the rapid release of VFA, causes SS alkalinity fail to control pH drop. On the contrary, at mesophilic temperature range the process performs steadily, with 148% increase in methane production when CGY represented 1% v/v of the influent (27% of influent COD). Further CGY percentages did not show any added improvement; the biomass shift, due to a high C/N ratio, could explain this behaviour. Results suggested that CGY can be used as co-substrate of SS anaerobic digestion though, depending on the characteristics of CGY, and on operational conditions, different parameters should be taken into account to achieve a steady and consistent operation.
authors.affiliation: IRTA, GIRO Joint Research Unit IRTA-UPC, Torre Marimon, E-08140 Caldes de Montbui, Barcelona, Spain.
authors.forename: G
authors.initials: G
authors.lastname: Silvestre
authors.affiliation: IRTA, GIRO Joint Research Unit IRTA-UPC, Torre Marimon, E-08140 Caldes de Montbui, Barcelona, Spain.
authors.forename: B
authors.initials: B
authors.lastname: Fernández
authors.affiliation: IRTA, GIRO Joint Research Unit IRTA-UPC, Torre Marimon, E-08140 Caldes de Montbui, Barcelona, Spain. Electronic address: august.bonmati@irta.cat.
authors.forename: A
authors.initials: A
authors.lastname: Bonmatí
mesh_terms: D000693:Anaerobiosis / Q000187:drug effects; D001673:Biodegradation, Environmental / Q000187:drug effects; D056804:Biofuels / Q000032:analysis; D018533:Biomass; D019149:Bioreactors / Q000382:microbiology; D002244:Carbon / Q000032:analysis*; D005990:Glycerol / Q000494:pharmacology*; D008697:Methane / Q000096:biosynthesis; D009584:Nitrogen / Q000032:analysis*; D012722:Sewage / Q000737:chemistry*; D013696:Temperature; D014865:Waste Disposal, Fluid / Q000379:methods*; D014867:Water
chemical_list: D056804:Biofuels; D012722:Sewage; D014867:Water; D002244:Carbon; D009584:Nitrogen; D008697:Methane; D005990:Glycerol
keywords: Crude glycerine; Dewatering properties; Inhibition; Sewage sludge; Thermophilic and mesophilic co-digestion