Biological reactor resistance to inhibition

Abstract

The phenomenon of complete substrate conversion within biological reactors in the presence of toxic compounds, called the Reactor Resistance to Inhibition (RRI), has been investigated. It was theoretically demonstrated that the RRI value, which means the highest concentration of inhibitor by which complete substrate conversion is possible, depends on liquid detention time. The excess detention time over that required for complete conversion, imply the existence of a "reserve" reaction potential. The value of this "reserve" can be reduced by inhibitor action with no influence on the observed substrate conversion rate. The influence of detention time on biological denitrification in Packed Bed Reactors in the presence of chromium Cr6+ was investigated. The RRI value for 1 h detention time was 1.5 mg l-1 Cr6+ . For 3 h detention time the RRI value was 22 mg I-1 Cr6+ . The relationship between the RRI value and detention time was linear.