SIMULTANEOUS DETERMINATION OF INHIBITION-KINETICS OF CARBON OXIDATIONAND NITRIFICATION WITH A RESPIROMETER

This paper presents a new method for the simultaneous determination of inhibition kinetics of both carbon oxidation and nitrification with t he RODTOX (Rapid Oxygen Demand and TOXicity tester) respirometric bios ensor. The biokinetic parameters of carbon oxidation and nitrification are estimated on the basis of respirometric data obtained from batch experiments with pulse injection of a mixture of a readily biodegradab le carbon (acetic acid) and nitrogen (ammonium chloride) source. This estimation is based on a Double Monod mathematical model and a nonline ar parameter estimation algorithm. Performing batch tests with six to eight different concentrations of a toxic compound allows the deductio n of the dependence of the kinetic parameters on the toxicant concentr ations. The time necessary for a complete determination of the inhibit ion kinetics is approx. 8 h. Practical applications of the developed m ethod are given.