Patent · US Expired

Nitrogen and phosphorus removal from wastewater

US4522722A · kind A · utility

47Cited by
1References
4Claims
0Family size

Assignee

Inventor

Key dates

Filing dateMar 7, 1983
Grant dateJun 11, 1985
Priority date
Expiry dateMar 7, 2003

Classification

  • Technology area (CPC Y)Emerging Cross-Sectional Technologies
  • CPC primaryY02W10/10
  • WIPO fieldEnvironmental technology
  • WIPO sectorChemistry

Abstract

Wastewater is passed sequentially through an anaerobic treating zone and an oxic treating zone, followed by separation from the treated liquor of a dense sludge containing activated biomass, a least part of which is recycled to provide the activated biomass employed in treating the influent wastewater. Of the part of the sludge so recycled a minor portion is introduced into the anaerobic treating zone for admixture with the wastewater influent and the remaining major portion is introduced into the oxic treating zone, into which oxic zone oxygen-containing gas is admitted to effect oxygenation of the contents of that zone.

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