Patent ID: 6093322
Filing Date: 2000-07-25
Classification: C02F,Y10S

Abstract:
A process for controlling and regulating a nitrification and denitrification phase in a waste water treatment, the process comprising:measuring a redox potential (U.sub.R) of the waste water, the redox potential including an inflection point which is used for indication of the end of the denitrification phase;calculating an increase from at least two measurements of the redox potential, the at least two measurements being separated in time;storing the at least two measurements;comparing at least two sequential increase values of the redox potential with one another;generating a first switch-off signal (S1) based on the comparison between the at least two sequential increase values, the first switch-off signal for switching off the denitrification phase;detecting a maximum of the redox potential;detecting the redox potential for a period of time at a point where the denitrification phase is switched off;calculating a difference between the maximum redox potential and the redox potential for the period of time, the difference being representative of a present detection cycle;comparing the difference of the present detection cycle with the difference calculated in a previous detection cycle; andgenerating a second switch-off signal (S2) based on the comparison between the difference between the present and previous detection cycles, wherein the first and second switch-off signals (S1, S2) are used for switching off the denitrification phase.