Patent · US Expired

Orbal wastewater treatment process

US4975197A · kind A · utility

41Cited by
12References
9Claims
0Family size

Assignee

Inventors

Key dates

Filing dateFeb 8, 1990
Grant dateDec 4, 1990
Priority date
Expiry dateFeb 8, 2010

Classification

  • Technology area (CPC Y)Emerging Cross-Sectional Technologies
  • CPC primaryY10S210/926
  • WIPO fieldEnvironmental technology
  • WIPO sectorChemistry

Abstract

In an orbal wastewater treatment process including a plurality of concentric, annular basins or channels having surface aeration means, wastewater and recycled activated sludge are mixed in a first channel by a combination of the surface aeration means and introducing an oxygen-containing gas such as air into the lower portion of the zone under conditions which produce a complete mix reaction and sufficient oxygen is supplied to meet the biological oxygen demands of the mixed liquor. The gas is introduced, preferably by a plurality of fine bubble membrane diffusers, in the form of fine bubbles having a diameter of less than about 4 mm. The mixed liquor is sequentially oxidized in second and third channels by a combination of surface aeration means and introducing an oxygen-containing gas into the lower portions of the channels, preferably by fine bubble membrane diffusers.

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