Patent ID: 7083728

Claim:
A method of producing a treated sludge product comprising: (a) forming a sludge mixture by mixing untreated sludge with at least one alkaline material in an amount sufficient to raise pH of the sludge mixture to a level of at least about 12 and to increase percent solids in the sludge mixture to at least about 40% by weight; (b) forming a dried sludge mixture by drying the sludge mixture from step (a) in a direct or indirect dryer thereby increasing the percent solids thereof to at least about 50% by weight; (c) recycling a portion of the dried sludge mixture from step (b) to step (a); and (d) pasteurizing the dried sludge mixture from step (b) at a temperature at or above about 52° C. to form a treated sludge product.