COMPARISON BETWEEN CLASSICAL STEADY STATE AND RESPIROMETRIC TECHNIQUES TO EVALUATE BIODEGRADATION KINETICS IN A FOOD INDUSTRY WASTEWATER

CONTRERAS E.; BERTOLA N.; ZARITZKY N.

Puebla, Mexico

Congreso; ICEF8; 2000

In the present work microbial kinetic parameters in a continuous activated sludge reactor were determined using as wastewater a model system of a typical potato processing plant. Continuous feed system under steady state conditions (classical method) and a respirometric technique were used to compare microbial parameters. The effects of operating conditions in the continuous aerobic reactor on microbial growth and flora composition were analyzed using lab-scale continuous stirred-tank reactors at different dilution rates. Parameters of microbial growth were assessed with the mass balances of substrate consumption, biomass production, and product formation. As dilution rate increased, substrate concentration in the reactor increased and dissolved oxygen decreased; a change in microbial composition was observed and sludges showed dominant filamentous bacterial population. The respirometric technique constitutes a rapid and easy method to determine microbial kinetic parameters; however it does not lead to similar results as the classical method due to differences in the physiological state and microbial composition of the sludge affect the measured parameters.