Patent · US Expired

Cyclic, multi-stage biological process for wastewater treatment

US4975196A · kind A · utility

0Cited by
6References
7Claims
0Family size

Assignee

Inventor

Key dates

Filing dateApr 16, 1990
Grant dateDec 4, 1990
Priority date
Expiry dateApr 16, 2010

Classification

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

Abstract

A method for anaerobic biological waste treatment in multiple stages wherein a relatively high strength wastewater is introduced into a first biological reactor to produce an effluent of reduced strength, the effluent is passed into a second biological reactor for reaction therein, passage of the effluent into the second biological reactor is continued until the biological solids in the second reactor enter into a negative growth phase and become relatively stable, whereupon the flow of waste through the reactors is reversed by terminating introduction of the waste into the first reactor and passing the same into the second reactor to cause microorganisms in the second reactor to enter into a positive growth phase and the solids in the first reactor to enter into a negative growth phase.

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