Modeling of Energy Spilling in Substrate-Sufficient Cultures
Publication: Journal of Environmental Engineering
Volume 125, Issue 6
Abstract
A concept of an energy spilling coefficient between anabolism and catabolism was developed. Based on this concept, two models were proposed to describe quantitatively the effect of a substrate on the coefficient for substrate-sufficient continuous and batch cultures. The models have been well verified using literature data obtained from the continuous cultures of Bacillus strains and the writers' own data obtained from both anoxic and aerobic batch cultures of activated sludge microorganisms. It has also been demonstrated that in both types of cultures, with an increasing residual substrate concentration or increasing initial food-to-microorganisms ratio, a decline of observed growth yield (Yobs) was mainly due to energy spilling. The effect of the substrate on the energy spilling coefficient in the substrate-sufficient cultures can be expressed by a Monod type curve. In the continuous cultures, the maximum energy spilling coefficient was found to be 0.7 when the residual methanol concentrations were greater than 10 mmol/L. In the batch cultures, the efficiency of anoxic sludge reached 0.8 as the initial food-to-microorganisms ratio exceeded 10 mg chemical oxygen demand/mg mixed-liquor suspended solids, while that of aerobic sludge was only 60% with the same ratio. These findings reveal that anoxic activated sludge has a higher potential of energy spilling than does aerobic sludge.
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References
1.
Brooke, A. G., Attwood, M. M., and Tempest, D. W. ( 1990). “Metabolic fluxes during the growth of thermotolerant methylotrophic Bacillus strains in methanol-sufficient continuous cultures.” Arch. Microbiol., 153, 591–595.
2.
Chang, J. ( 1988). “Etude cinétique et modélisation de la croissance d'une population mixte sur substrat complexe par cuoplage d'un réacteur discontinu à un spectrométre de masse,” PhD thesis, Institut National des Sciences Appliquées, Toulouse, France (in French).
3.
Chang, J., Chudoba, P., and Capdeville, B. ( 1993). “Determination of the maintenance requirements of activated sludge.” Water Sci. and Technol., 28, 139–142.
4.
Chen, G. H., Yip, W. K., and Liu, Y. ( 1999). “Effect of low ORP exposure of aerobic and anoxic activated sludge on observed growth yield.” Water Res., in preparation.
5.
Chudoba, J. ( 1969). “Residual organic matter in activated sludge processes effluents V. Effluent of the initial food-to-microorganisms ratio.” Scientific Paper, Institute of Chemical Technology, Prague, Czech Republic, 23–34.
6.
Chudoba, P., Capdeville, B., and Chudoba, J. ( 1992). “Explanation of biological meanings of the S0/X0 ratio in batch cultivation.” Water Sci. and Technol., 26, 743–751.
7.
Fiechter, A., and Seghezzi, W. ( 1992). “Regulation of glucose metabolism in growing yeast cells.” J. Biotechnol., 27, 27–45.
8.
Forrest, W. W. ( 1969). “Energetic aspects of microbial growth.” Microbial Energetics, Cambridge University Press, London, 65–86.
9.
Gokcay, C. F., and Yetis, U. ( 1996). “Effect of nickel (II) on the biomass yield of the activated sludge.” Water Sci. and Technol., 34(5/6), 163–171.
10.
Hueting, S., and Tempest, D. W. ( 1979). “Influence of the glucose input concentration on growth kinetics of metabolite production by Klebsiella aerogenes NCTC 418: Growing in continuous culture in potassium- or ammonia-limited environments.” Arch. Microbiol., 123, 189–194.
11.
Liu, Y. ( 1996a). “Bioenergetic interpretation of the S0/X0 ratio in substrate-sufficient batch culture.” Water Res., 30, 2766–2770.
12.
Liu, Y. ( 1996b). “A growth yield model for substrate-sufficient continuous culture of microorganisms.” Envir. Technol., 17, 649–653.
13.
Liu, Y., and Chen, G. H. ( 1997). “Model of energy uncoupling for substrate-sufficient culture.” Biotechnol. and Bioengrg., 55, 571–575.
14.
Liu, Y., Chen, G. H., and Paul, E. ( 1998). “Effect of the S0/X0 ratio on energy uncoupling in substrate-sufficient batch culture of activated sludge.” Water Res., 32, 2883–2888.
15.
Mo, H. K. ( 1998). “Minimization of activated sludge production by utilization of energy spilling stimulator-TCS,” MS thesis, Hong Kong University of Science and Technology, Kowloon, Hong Kong.
16.
Neijssel, O. M., and Tempest, D. W. ( 1975). “The regulation of carbohydrate metabolism in Klebsiella aerogenes NCTC 418 organisms growing in continuous culture.” Arch. Microbiol., 106, 251–258.
17.
Pirt, S. J. ( 1965). “The maintenance energy of bacteria in growing cultures.” Proc., Royal Soc., London, B163, 224–231.
18.
Pirt, S. J. ( 1975). Principles of microbe and cell cultivation. Blackwell Scientific, London.
19.
Pitter, S. J., and Chudoba, J. ( 1990). Biodegradability of organic substances in the aquatic environment. CRS Press, Boca Raton, Fla.
20.
Rao, B. S., and Gaudy, A. F. Jr. ( 1966). “Effect of sludge concentration on various aspects of biological activity in activated sludge.” J. Water Pollution Control Fedn., 38, 794–812.
21.
Russell, J., and Cook, G. M. ( 1995). “Energetics of bacterial growth: Balance of anabolic and catabolic reaction.” Microbol. Rev., 95, 48–63.
22.
Speece, R. E., Engelbrecht, R. S., and Aukamp, D. R. ( 1973). “Cell replication and biomass in the activated sludge process.” Water Res., 7, 361–374.
23.
Standard method for examination of water and wastewater, 18th Ed. (1992). American Public Health Association, Washington, D.C.
24.
Stouthamer, A. H. ( 1977). “Energetic aspects of the growth microorganisms.” Microbial energetics, B. A. Haddock and W. A. Hamilton, eds., Cambridge University Press, London, 285–315.
25.
Stouthamer, A. H. ( 1979). “The search for correlation between theoretical and experimental growth yields. Int. Rev. Biochem., 21, 1–15.
26.
Tempest, D. W., and Neijssel, O. M. ( 1984). “The status of YATP and maintenance energy as biologically interpretable phenomena.” Annu. Rev. Microbiol., 38, 459–486.
27.
Tsai, S. P., and Lee, Y. H. ( 1990). “A model for energy-sufficient culture.” Biotechnol. and Bioengrg., 35, 138–145.
28.
Westerhoff, H. V., Lolkema, J. R., Otto, R., and Helingwerf, K. J. ( 1982). “Thermodynamics of growth: Non-equilibrium thermodynamics of bacterial growth—The phenomenological and the mosaic approach.” Biochem. Biophys. Acta, 683, 180–220.
29.
Yamane, T., Hibino, W., Ishihara, K., Kadotani, Y., and Kominami, M. ( 1992). “Fed-batch culture automated by uses of continuously measured cell concentration and culture volume.” Biotechnol. and Bioengrg., 39, 550–555.
30.
Zeng, A. P., and Deckwer, W. D. ( 1995). “A kinetic model for substrate and energy consumption of microbial growth under substrate-sufficient conditions.” Biotechnol. Progress, 11, 71–79.
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Received: Feb 13, 1997
Published online: Jun 1, 1999
Published in print: Jun 1999
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