title: Modeling of Anaerobic Digestion with a Focus on Estimation of Hydrolysis Constants at 35, 55, and 60 °C.
abstract: Hydrolysis constants of mixed sludge at 35, 55, and 60 °C were found to be 0.32, 0.44, and 0.50 1/d, respectively, in pilot-scale, semicontinuously operated anaerobic digesters. The hydrolysis constants and estimated chemical oxygen demand fractions in the feed were introduced to a mathematical model for anaerobic digestion published by Siegrist et al. (2002), which is similar to Anaerobic Digestion Model No. 1. First-order and Monod-type kinetics were tested for estimation of hydrolysis constants. The applied kinetics were found to affect the outcome of the regression study. Moreover, the free ammonia inhibition model was excluded for both propionate oxidation and acetate conversion, thanks to the apparent acclimatized biomass. No substantial accumulation of volatile fatty acids was observed in the reactors at 35, 55, and 60 °C, corresponding to free ammonia nitrogen concentrations of about 20, 110, and 130 g N/m³, respectively.
authors.affiliation: Water and Environmental Engineering, Department of Chemical Engineering, Lund University, Box 124, SE-221 00 LUND, Sweden.
authors.forename: Salar
authors.initials: S
authors.lastname: Haghighatafshar
authors.forename: Elin
authors.initials: E
authors.lastname: Ossiansson
authors.forename: Konrad
authors.initials: K
authors.lastname: Koch
authors.forename: Hamse
authors.initials: H
authors.lastname: Kjerstadius
authors.forename: Jes la Cour
authors.initials: Jl
authors.lastname: Jansen
authors.forename: Åsa
authors.initials: Å
authors.lastname: Davidsson
mesh_terms: D000693:Anaerobiosis; D057919:Biological Oxygen Demand Analysis; D019149:Bioreactors; D003198:Computer Simulation; D006868:Hydrolysis; D008697:Methane; D008954:Models, Biological; D015203:Reproducibility of Results; D013696:Temperature; D014865:Waste Disposal, Fluid / Q000379:methods*
chemical_list: D008697:Methane