The ADM1 was employed to assess the effect of variations in solids hydrolysis and acetoclastic methanogen process characterizations on municipal digester stability relating to excess acetate utilization capacity. First-order single- and dual-pathway hydrolysis rate functions and single and competitive acetoclastic methanogen rate functions were implemented in the ADM1. The acetate capacity number (ACN), defined as the ratio between the maximum acetate utilization rate and the average acetate production rate, was used to index digester instability. Simulations of a single CSTR at steady state indicate a similar ACN can be obtained with a 12-day SRT digester dominated by Methanosarcina sp and a 24-day SRT digester dominated by Methanosaeta sp. An increase in ACN with a decrease in SRT representing Methanosarcina sp. selection was observed for particulate feed loadings from 40 g COD/L to 90 g COD/L. Feeding frequency and dual-pathway hydrolysis were found to have less effect on the ACN than the competitive acetoclastic model structure.
[1]
Irini Angelidaki,et al.
Anaerobic Digestion Model (ADM1)
,
2002
.
[2]
W. Gujer,et al.
Mathematical model for meso- and thermophilic anaerobic sewage sludge digestion.
,
2002,
Environmental science & technology.
[3]
Jurg Keller,et al.
Mathematical Modelling of Two-Stage Anaerobic Digestion using IWA Anaerobic Digestion Model No.1 (ADM1)
,
2002
.
[4]
H. D. Stensel,et al.
Growth Kinetics and Competition Between Methanosarcina and Methanosaeta in Mesophilic Anaerobic Digestion
,
2006,
Water environment research : a research publication of the Water Environment Federation.
[5]
Hans-Joachim Jördening,et al.
Comparison of different models of substrate and product inhibition in anaerobic digestion
,
1999
.