Biosolids flow-through thermophilic treatment process

US6908555B2 · kind B2 · utility

Assignee

• Columbus Water Works · US

Inventors

• Clifford J. Arnett · Columbus, US
• Joseph B. Farrell · Cincinnati, US
• Daniel Hull · Chandler, US
• Steven J. Krugel · Seattle, US
• Perry Schafer · Sacramento, US
• Billy G. Turner · Columbus, US
• Warren R. Uhte · Yreka, US
• John L. Willis · Sidney Place, US

Key dates

• Filing date: Apr 28, 2003
• Grant date: Jun 21, 2005
• Expiry date: May 20, 2023

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C02F2301/106
• WIPO field: Biotechnology
• WIPO sector: Chemistry

Abstract

A method of treating wastewater sludge includes pumping, continuously, raw sludge into a first digester and treating the raw sludge at a specific temperature of between about 51° C. to 60° C.; transferring the treated wastewater sludge to a batch tank; treating the wastewater sludge in the batch tank, anaerobically, at a thermophilic temperature which is not more than 2° C. warmer than the specific temperature in the first digester; and disposing of the treated wastewater sludge as a Class A biosolid. A wastewater sludge treatment system includes a first thermophilic digester for treating raw wastewater sludge at a specific temperature in a range of between about 51° C. to 60° C., and discharging a treated wastewater sludge; a batch tank for receiving the treated wastewater sludge discharged from the first digester and for thermophilically treating sludge at a temperature in a range of between about 51° C. to 60° C. and not more than 2° C. warmer than the specific temperature in the first digester, for between about 0.5 hours and 5 hours; and a disposal mechanism for disposing of the treated wastewater sludge as a Class A biosolid.