title: Reactor performance and microbial community dynamics during anaerobic co-digestion of municipal wastewater sludge with restaurant grease waste at steady state and overloading stages.
abstract: Linkage between reactor performance and microbial community dynamics was investigated during mesophilic anaerobic co-digestion of restaurant grease waste (GTW) with municipal wastewater sludge (MWS) using 10L completely mixed reactors and a 20day SRT. Test reactors received a mixture of GTW and MWS while control reactors received only MWS. Addition of GTW to the test reactors enhanced the biogas production and methane yield by up to 65% and 120%, respectively. Pyrosequencing revealed that Methanosaeta and Methanomicrobium were the dominant acetoclastic and hydrogenotrophic methanogen genera, respectively, during stable reactor operation. The number of Methanosarcina and Methanomicrobium sequences increased and that of Methanosaeta declined when the proportion of GTW in the feed was increased to cause an overload condition. Under this overload condition, the pH, alkalinity and methane production decreased and VFA concentrations increased dramatically. Candidatus cloacamonas, affiliated within phylum Spirochaetes, were the dominant bacterial genus at all reactor loadings.
authors.affiliation: Department of Civil and Environmental Engineering, University of Alberta, 9105-116 St, T6G 2W2 Edmonton, Alberta, Canada. Electronic address: razaviar@ualberta.ca.
authors.forename: Vahid
authors.initials: V
authors.lastname: Razaviarani
authors.affiliation: Department of Civil and Environmental Engineering, University of Alberta, 9105-116 St, T6G 2W2 Edmonton, Alberta, Canada.
authors.forename: Ian D
authors.initials: ID
authors.lastname: Buchanan
mesh_terms: D000693:Anaerobiosis; D019149:Bioreactors / Q000382:microbiology*; D005735:Garbage; D059013:Microbial Consortia; D012722:Sewage
chemical_list: D012722:Sewage
keywords: Grease waste; Mesophilic anaerobic co-digestion; Microbial dynamics; Municipal wastewater sludge; Reactor performance