Theory of pH-stat titration.
Innovative techniques are being studied to assess the activity of bioreactors and to improve the performance and operational stability of biological processes. Among these techniques, the pH-stat titration is applicable to any bioreaction involving pH variations. Up to now, the main application of the pH-stat titration has been for nitrification monitoring. In this article, we present a theoretical model of pH-stat titration, which predicts the response to any reaction involving the production or consumption of protons, hydroxyl ions, or inorganic carbon chemical species (CO(2), HCO(3)(-), CO(3)(=)). This model is a useful tool to understand pH-stat titrations, to define their applicability and limits, and to select the best experimental conditions for specific applications. Tests have been performed to compare experimental pH-stat titration rates in the presence of carbon dioxide and HCO(3)(-) producing reactions to the values predicted by the model and a very satisfying correspondence was found.
Ficara
Elena
E
Dipartimento di Ing, Politecnico di Milano, Milan, Italy.
Rozzi
Alberto
A
Cortelezzi
Paola
P
D001639:Bicarbonates / Q000032:analysis / Q000737:chemistry / Q000378:metabolism; D019149:Bioreactors; D002245:Carbon Dioxide / Q000032:analysis / Q000737:chemistry / Q000378:metabolism; D002254:Carbonates / Q000032:analysis / Q000737:chemistry / Q000378:metabolism; D003198:Computer Simulation; D005246:Feedback; D006863:Hydrogen-Ion Concentration; D008954:Models, Biological; D008956:Models, Chemical; D017186:Titrimetry / Q000295:instrumentation* / Q000379:methods*
D001639:Bicarbonates; D002254:Carbonates; D002245:Carbon Dioxide