Patent · US Expired

Process for the secondary treatment of wastewater

US4374027A · kind A · utility

20Cited by
12References
9Claims
0Family size

Assignee

Inventors

Key dates

Filing dateFeb 26, 1979
Grant dateFeb 15, 1983
Priority date
Expiry dateFeb 26, 1999

Classification

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

Abstract

A process for the secondary treatment of wastewater by a modified air activated sludge system comprising aerating wastewater containing bacteria until the BOD level of the wastewater is reduced by at least 90%, the food to microorganism ratio of the wastewater being greater than one, introducing the aerated wastewater under pressure to a flotation cell to separate suspended solids including bacteria from the pressurized wastewater by dissolved air flotation clarification, recycling said suspended soilds and bacteria to said aeration step in an amount sufficient to maintain said food to microorganism ratio and removing and disposing of the remaining reduced BOD level wastewater.

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