||Alternative Nonlinear Model for Estimating Second-Order Rate Coefficients for Biodegradation.
Suflita, J. M. ;
Smolenski, W. J. ;
Robinson, J. A. ;
||Oklahoma Univ., Norman. Dept. of Botany and Microbiology. ;Upjohn Co., Kalamazoo, MI.;Robert S. Kerr Environmental Research Lab., Ada, OK.
||EPA-R-811146 ;EPA-R-812808; EPA/600/J-87/132;
Anaerobic conditions ;
Mathematical models ;
Nonlinear programming ;
||Most EPA libraries have a fiche copy filed under the call number shown. Check with individual libraries about paper copy.
A modification of the second-order model for biodegradation was derived, applied to an example data set and shown to be superior for describing the anaerobic biodegradation of p-cresol by an enriched bacterial consortium. The modified model circumvents the no-growth assumption implicit in the use of the second-order rate equation, but still requires the assumption of first-order kinetics over the course of substrate depletion. Violation of the no-growth assumption is particularly important since overestimates of the pseudo-first-order rate coefficient lead to underestimates of the time required for the removal of a xenobiotic chemical from a contaminated environment. Calculations show that the errors introduced into the pseudo-first-order rate coefficient (and the resulting estimates of the second-order rate coefficient) approach 100% if one doubling occurs in activity over the course of substrate depletion. (Copyright (c) 1987, American Society for Microbiology.)