Patent · US Expired

Process for controlling an aeration tank in an activated sludge sewage treatment

US4437992A · kind A · utility

19Cited by
4References
7Claims
0Family size

Assignee

Inventors

Key dates

Filing dateMar 5, 1982
Grant dateMar 20, 1984
Priority date
Expiry dateMar 5, 2002

Classification

  • Technology area (CPC Y)Emerging Cross-Sectional Technologies
  • CPC primaryY02W10/10
  • WIPO fieldMeasurement
  • WIPO sectorInstruments

Abstract

It is necessary for maintaining a good assimilating characteristic of microorganisms upon organic matter in an aeration tank to control a gas flow rate and a return sludge flow rate to optimum values. To this effect, it is necessary to know a concentration of organic matter or a organic load. In the present invention, it is confirmed that carbon dioxide (CO.sub.2) or nitrous oxide (N.sub.2 O) in an exhaust gas from the aeration tank has a correlation with it, and the aeration tank is controlled as N.sub.2 O or CO.sub.2 as an index. Furthermore, it is confirmed that CO.sub.2 formation rate has a good correlation with COD or BOD in the upstream half section of the aeration tank, whereas N.sub.2 O formation rate has a good correlation with COD or BOD in the latter half section thereof along sewage flow direction, and more improved control can be attained by a combination of both CO.sub.2 and N.sub.2 O indices.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.