Patent ID: 7497956

Claim:
Process for stabilizing and conditioning wastewater sludge, comprising the steps of: a) treating the sludge simultaneously with an inorganic acid and an aqueous solution of a ferric iron salt and hydrogen peroxide to obtain an acidified sludge having a pH comprised between 4.0 and 5.5, the solution of ferric iron salt being used in an amount between 5 and 40 kg Fe/ton of dry sludge and the hydrogen peroxide being used in an amount between 5 and 40 kg H 2 O 2 /ton of dry sludge; b) mixing the treated sludge for a period of time sufficient to stabilize the sludge and improve dehydration capacity thereof; c) flocculating the stabilized sludge having a pH between 4.0 and 5.0 by addition of an organic polymer; and d) dehydrating the flocculated sludge, to produce a stabilized sludge which has reduced odor production during storage wherein the process steps are performed at room temperature to a temperature of 65° C.