Patent · US Expired

Shipboard wastewater treatment system

US6361695B1 · kind B1 · utility

103Cited by
20References
37Claims
0Family size

Assignee

Inventors

Key dates

Filing dateSep 30, 2000
Grant dateMar 26, 2002
Priority date
Expiry dateSep 30, 2020

Classification

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

Abstract

A method and system for treating wastewater in an onboard ship sewage treatment system having controlled suspended solids, the method comprising the steps of collecting wastewater in a collection tank and transferring the wastewater to a bioreactor to oxidize organic material contained in the wastewater by adding oxygen-containing gas thereto. The bioreactor is operated to provide a mixed liquor having a solids concentration of at least 5 g/l and the solids concentration is continuously increased in the mixed liquor in the bioreactor to not greater than 30 g/l. When the solids concentration in the mixed liquor reaches at least 15 g/l, a portion of the mixed liquor is removed from the bioreactor. Thereafter, wastewater is added to the bioreactor to decrease the solids concentration of remaining or residual mixed liquor to not less than 5 g/l. The bioreactor is further operated to increase the solids content again. A hollow fiber membrane is used to remove water from the mixed liquor to provide treated effluent.

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