Detection of very low saturation constants in anaerobic digestion: Influences of calcium carbonate precipitation and pH

Abstract Samples taken from a fluidized-bed reactor revealed very low saturation constants for the degradation of acetate (2–12 mg/l) and propionate (<3 mg/l). The higher values for the acetate degradation appear to be caused by mass-transport limitation due to calcium carbonate precipitation within the biofilm. The intrinsic saturation constant is about 3 mg/l, which is significantly lower than previously published values for pure and mixed cultures. The influence of the pH on the saturation constant was investigated in fed-batch experiments. Contrary to the hypothesis that only the undissociated acid is the effective substrate, no significant influence of pH on the saturation constant (given as concentration of total acid) was observed. Batch experiments with n-butyrate revealed hyperbolic progress curves, which might be misinterpreted as a sign of a high saturation constant. However, fed-batch experiments showed that, for n-butyrate degradation, the saturation constant is very low. The isomerisation to isobutyrate and other side-reactions, for which indications were found, influence the progress curve such that an elevated saturation constant will result as an artifact. Thus saturation constants for n-butyrate degradation obtained from batch experiments have to be viewed critically.

[1]  John F. Andrews,et al.  Dynamic Model of the Anaerobic Digestion Process , 1969 .

[2]  Shiro Nagai,et al.  Kinetics of the Methanogenic Fermentation of Acetate , 1990, Applied and environmental microbiology.

[3]  Daniel P. Smith,et al.  Reduced product formation following perturbation of ethanol‐ and propionate‐fed methanogenic CSTRs , 1989, Biotechnology and bioengineering.

[4]  G. Patel,et al.  Characterization and nutritional properties of Methanothrix concilii sp. nov., a mesophilic, aceticlastic methanogen , 1984 .

[5]  U. Wiesmann,et al.  Degradation kinetics of acetate and propionate by immobilized anaerobic mixed cultures , 1995 .

[6]  B. Schink,et al.  Reciprocal Isomerization of Butyrate and Isobutyrate by the Strictly Anaerobic Bacterium Strain WoG13 and Methanogenic Isobutyrate Degradation by a Defined Triculture , 1992, Applied and environmental microbiology.

[7]  Shangtian Yang,et al.  Kinetic study and mathematical modeling of methanogenesis of acetate using pure cultures of methanogens , 1987, Biotechnology and bioengineering.

[8]  J. Lema,et al.  Degradation of volatile fatty acids by differently enriched methanogenic cultures: Kinetics and inhibition , 1995 .

[9]  J. Lema,et al.  Kinetic modelling of isomerization and anaerobic degradation of n- and i-butyrate , 1990 .

[10]  R. J. Hall,et al.  Kinetics of two subgroups of propionate-using organisms in anaerobic digestion , 1983, Applied and environmental microbiology.

[11]  John A. Nelder,et al.  A Simplex Method for Function Minimization , 1965, Comput. J..

[12]  Shiro Nagai,et al.  Inhibition of the Fermentation of Propionate to Methane by Hydrogen, Acetate, and Propionate , 1990, Applied and environmental microbiology.

[13]  William H. Press,et al.  The Art of Scientific Computing Second Edition , 1998 .

[14]  E. Samain,et al.  Isomerization between n‐butyrate and isobutyrate in enrichment cultures , 1988 .

[15]  William H. Press,et al.  Numerical Recipes in Fortran 77: The Art of Scientific Computing 2nd Editionn - Volume 1 of Fortran Numerical Recipes , 1992 .

[16]  Arnold Eucken,et al.  Zahlenwerte und Funktionen aus Physik, Chemie, Astronomie, Geophysik und Technik , 1950 .

[17]  D. S. Riggs,et al.  A COMPARISON OF ESTIMATES OF MICHAELIS-MENTEN KINETIC CONSTANTS FROM VARIOUS LINEAR TRANSFORMATIONS. , 1965, The Journal of biological chemistry.

[18]  R. Gourdon,et al.  Kinetics of acetate, propionate and butyrate removal in the treatment of a semi‐synthetic landfill leachate on anaerobic filter , 1989, Biotechnology and bioengineering.

[19]  G. Atkins,et al.  A comparison of seven methods for fitting the Michaelis-Menten equation. , 1975, The Biochemical journal.

[20]  Heinzle,et al.  Dynamic determination of anaerobic acetate kinetics using membrane mass spectrometry , 1998, Biotechnology and bioengineering.

[21]  M. Nihtilä,et al.  Practical identifiability of growth and substrate consumption models , 1977, Biotechnology and bioengineering.

[22]  Mogens Henze,et al.  Anaerobic Treatment of Wastewater in Fixed Film Reactors – A Literature Review , 1983 .

[23]  K. Wuhrmann,et al.  Kinetic parameters and relative turnovers of some important catabolic reactions in digesting sludge , 1978, Applied and environmental microbiology.

[24]  W. Gujer,et al.  Mathematical Modelling of Anaerobic Mesophilic Sewage Sludge Treatment , 1993 .

[25]  R. Mah,et al.  Growth and Methanogenesis by Methanosarcina Strain 227 on Acetate and Methanol , 1978, Applied and Environmental Microbiology.

[26]  D. Verrier,et al.  Dynamic modelling of anaerobic digestion , 1986 .

[27]  Christian Wandrey,et al.  Continuous Anaerobic Digestion with Methanosarcina barkeri , 1983 .

[28]  T. Noike,et al.  Characteristics of carbohydrate degradation and the rate‐limiting step in anaerobic digestion , 1985, Biotechnology and bioengineering.

[29]  J. Zeikus,et al.  Perturbation of syntrophic isobutyrate and butyrate degradation with formate and hydrogen , 2000, Biotechnology and bioengineering.

[30]  Tatsuya Noike,et al.  A Kinetic Study on the Methanogenesis Process in Anaerobic Digestion , 1989 .

[31]  Axel Munack,et al.  Optimal Feeding Strategy for Identification of Monod-Type Models by Fed-Batch Experiments , 1989 .

[32]  Matthias Reuss,et al.  Optimal Experimental Design for Parameter Estimation in Unstructured Growth Models , 1994 .