title: Biomethanation and microbial community changes in a digester treating sludge from a brackish aquaculture recirculation system.
abstract: Using a high-salinity-adapted inoculum and a moderate stepwise-increased organic loading rate (OLR), a stable digester performance was achieved in treating sludge from a brackish aquaculture recirculation system. The specific methane yield was distinctly enhanced, reaching 0.203LCH4/gCODadded, compared to literature values (0.140-0.154LCH4/gCODadded) from the salty sludges. OLR adjustment and the fecal substrate substantially influenced population changes in the digester. Within the bacterial subpopulations, the relative abundance of Bacillus and Bacteroides declined, accompanied by the increase of Clostridium and Trigonala over time. The results show Trigonala was derived from the substrate and accumulated inside the digester. The most abundant methanogen was Methanosarcina in the inoculum and the digestates. The Methanosarcina proliferation can be ascribed to its metabolic versatility, probably a feature of crucial importance for high-salinity environments. Other frequently observed methanogens were outcompeted. The population similarity at the genus level between inoculum and digestates declined during the initial stage and afterwards increased.
authors.affiliation: Section Sanitary Engineering, Department of Water Management, Delft University of Technology, Stevinweg 1, 2628CN Delft, The Netherlands. Electronic address: x.zhang@tudelft.nl.
authors.forename: Xuedong
authors.initials: X
authors.lastname: Zhang
authors.affiliation: Department of Chemical Engineering, Imperial College London, South Kensington Campus, London, UK.
authors.forename: Yu
authors.initials: Y
authors.lastname: Tao
authors.affiliation: Section Sanitary Engineering, Department of Water Management, Delft University of Technology, Stevinweg 1, 2628CN Delft, The Netherlands.
authors.forename: Jianmei
authors.initials: J
authors.lastname: Hu
authors.affiliation: Section Sanitary Engineering, Department of Water Management, Delft University of Technology, Stevinweg 1, 2628CN Delft, The Netherlands; Oasen Water Company, PO Box 122, 2800 AC Gouda, The Netherlands.
authors.forename: Gang
authors.initials: G
authors.lastname: Liu
authors.affiliation: Section Sanitary Engineering, Department of Water Management, Delft University of Technology, Stevinweg 1, 2628CN Delft, The Netherlands.
authors.forename: Henri
authors.initials: H
authors.lastname: Spanjers
authors.affiliation: Section Sanitary Engineering, Department of Water Management, Delft University of Technology, Stevinweg 1, 2628CN Delft, The Netherlands.
authors.forename: Jules B
authors.initials: JB
authors.lastname: van Lier
mesh_terms: D064751:Ammonium Compounds / Q000032:analysis; D017756:Aquaculture / Q000379:methods*; D001105:Archaea / Q000378:metabolism*; D001419:Bacteria / Q000378:metabolism*; D061249:Batch Cell Culture Techniques; D001673:Biodegradation, Environmental; D044822:Biodiversity; D056804:Biofuels / Q000032:analysis; D019149:Bioreactors / Q000382:microbiology; D006863:Hydrogen-Ion Concentration; D008697:Methane / Q000378:metabolism*; D010802:Phylogeny; D054712:Salinity; D012722:Sewage / Q000382:microbiology*
chemical_list: D064751:Ammonium Compounds; D056804:Biofuels; D012722:Sewage; D008697:Methane
keywords: Anaerobic digestion; Bacterial and archaeal population; Brackish aquaculture recirculation systems; Inoculum; Sludge retention time (SRT); Stepwise increased OLR