title: The steady state anaerobic digestion of Laminaria hyperborea--effect of hydraulic residence on biogas production and bacterial community composition.
abstract: Methane production by anaerobic digestion (AD) of macroalgae (seaweed) is a promising algal bioenergy option. Work presented here is primarily based on the AD of Laminaria hyperborea using batch and continuously stirred tank reactors. Extrapolation of data from batch studies to long term continuous reactors was unreliable. A conservative organic loading rate (OLR) of 1 g L(-1) d(-1) was used due to difficulties experienced in achieving steady state performance at an OLR of 1.5 g L(-1) d(-1). Biogas composition and methane yields (60-70%) were near to values expected from terrestrial feedstocks. Biomass washout, as imposed by the dilution rate (i.e., hydraulic residence), had considerable bearing on the biogas generation profile, particularly at >3 hydraulic residences. Inhibition of methanogen growth was linked to nutrient deficiency and potentially antimicrobial compounds associated with the feedstock. Anaerobic digestion of L. hyperborea proved feasible over extended operational periods.
authors.affiliation: School of Civil Engineering and Geosciences, Cassie Building, Claremont Road, Newcastle University, Newcastle Upon Tyne NE1 7RU, UK. jhinks@ntu.edu.sg
authors.forename: Jamie
authors.initials: J
authors.lastname: Hinks
authors.forename: Stephen
authors.initials: S
authors.lastname: Edwards
authors.forename: Paul J
authors.initials: PJ
authors.lastname: Sallis
authors.forename: Gary S
authors.initials: GS
authors.lastname: Caldwell
mesh_terms: D000693:Anaerobiosis; D001419:Bacteria / Q000145:classification / Q000378:metabolism*; D056804:Biofuels; D019149:Bioreactors; D007795:Laminaria / Q000378:metabolism*; D013045:Species Specificity
chemical_list: D056804:Biofuels
keywords: Anaerobic digestion; Biofuel; Biogas; Brown algae; Seaweed