Patent · US Expired

Wastewater treatment process

US5128040A · kind A · utility

35Cited by
13References
24Claims
0Family size

Assignee

Inventors

Key dates

Filing dateAug 2, 1989
Grant dateJul 7, 1992
Priority date
Expiry dateAug 2, 2009

Classification

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

Abstract

A wastewater treatment process having improved solids separation characteristics and reduced biochemical oxygen demand (BOD) in the purified wastewater comprising the steps of: passing wastewater containing suspended solids and biodegradable organic substances through an aerobic biological oxidation zone and therein oxidizing a portion of the BOD and converting a portion of the BOD into additional suspended solids; passing the effluent from said aerobic biological oxidation zone to an aerobic/mixing zone and therein mixing said effluent with effluent from the anoxic/anaerobic zone; passing the effluent from said aerobic/mixing zone to a settling zone and therein separating purified wastewater having reduced BOD and suspended solids, and sludge containing suspended solids; passing a portion of the sludge formed in the settling zone to an anoxic/anaerobic zone and therein increasing the extracellular polymer content of said sludge; and recycling an effective amount of the effluent from said anoxic/anaerobic zone to said aerobic/mixing zone.

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