Patent · US Expired

Method and installation for treating effluents, comprising an additional treatment of the sludge by ozonization

US6780319B1 · kind B1 · utility

14Cited by
0References
9Claims
0Family size

Assignee

Inventors

Key dates

Filing dateJun 28, 2002
Grant dateAug 24, 2004
Priority date
Expiry dateDec 31, 2022

Classification

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

Abstract

Method of purifying wastewater charged with organic matter which comprises a step of biologically treating the water, during which the organic matter contained in the water is degraded by micro-organisms thereby producing sludge, and a water-sludge separation step, the sludge coming from the separation step being recycled in the biological treatment step, this method being characterized in that it further comprises a step of degrading the sludge, coming either from the biological treatment step or from the separation step, during which the sludge is brought into contact with an ozonated gas under conditions making it possible to obtain a floc consisting of granules whose mean size is greater than 200 microns, the volatile matter content is between 50 and 65%, the thickening factor of this granular sludge, after 30 minutes of settling, always being greater than 4, the conditions for obtaining the said granular sludge consisting in:treating between 0.1 and 2 times the mass of sludge present in the biological treatment step per day and preferably between 0.7 and 1.5 and,applying an ozone dose of between 3 and 100 grams of ozone per kilogram of treated suspended matter (SM), preferably…

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