Patent ID: 7452465
Filing Date: 2008-11-18
Classification: C02F,Y02E,Y02W

Abstract:
1. A two stage sludge treatment process comprising: a first pathogen reduction stage in which raw sludge is incubated for a predetermined incubation period at a temperature in the mesophilic temperature range of about 25° C. to about 46° C.; wherein the total chemical oxygen demand (COD) of the raw sludge is greater than about 10,000 mg/l and wherein the raw sludge is incubated in a plurality of sequential vessels comprising an upstream vessel which receives the raw sludge to be incubated and a downstream vessel which discharges the incubated sludge, the sludge being fed from the upstream vessel to the downstream vessel, via any intermediate vessels, to provide a total residence time of between 0.5 and 5 days and subsequently being fed to a suitable reactor for mesophilic anaerobic digestion of the sludge after spending a predetermined residence time in each vessel, the total residence time being said predetermined incubation period.