Patent ID: 8464437

Claim:
A method for treatment of sewage sludge containing a pathogen, comprising: cascading sewage sludge containing water and at least one pathogen between a plurality of supports vertically stacked within an upper portion and a lower portion of a processing chamber; heating the sewage sludge while cascading between the supports within the upper portion of the processing chamber to remove a portion of the water within the sewage sludge thereby forming a reduced water content sewage sludge; heating the reduced water content sewage sludge within the lower portion of the processing chamber for a sufficient time and at a sufficient temperature to reduce the amount of the at least one pathogen thereby forming a treated sewage sludge; exiting exhaust gas created in the upper and lower portions of the processing chamber; recycling at least a portion of the exhaust gas to the processing chamber for heating the sewage sludge contained therein; supplying heated gas to the upper portion of the processing chamber for removing a portion of the water contained within the sewage sludge and to the lower portion of the processing chamber for reducing the amount of the at least one pathogen within the sewage sludge; and controlling the temperature of the heated gas within the processing chamber below the ignition temperature of the sewage sludge to prevent the formation of embers therefrom.