Data was obtained for a direct comparison between the freeze conditioning and dewatering technique and the conditioning and dewatering methods presently employed at Milwaukee, Wisconsin. The laboratory investigation phase resulted in a freeze-conditioning system consisting of the following process elements: Flotation thickening prior to freezing, Freezing in thin sheets, Thawing of the frozen product, and Dewatering of the thawed sludge. The objective of the engineering design phase was the development of a freeze-conditioning system to handle three tons dry solids per day of activated sludge. Although the freeze conditioning concept, from a technical standpoint, has definite merit as a sludge conditioning process, the equipment capital costs, operating costs, and space requirements are appreciably greater for the freeze conditioning process than for the present chemical conditioning method. (Author)

"January. 1971." "Prepared for the Environmental Protection Agency under grant #WPRD 71-01-68." Includes bibliographical references (page 47).

Data was obtained for a direct comparison between the freeze conditioning and dewatering technique and the conditioning and dewatering methods presently employed at Milwaukee, Wisconsin. The laboratory investigation phase resulted in a freeze-conditioning system consisting of the following process elements: Flotation thickening prior to freezing, Freezing in thin sheets, Thawing of the frozen product, and Dewatering of the thawed sludge. The objective of the engineering design phase was the development of a freeze-conditioning system to handle three tons dry solids per day of activated sludge. Although the freeze conditioning concept, from a technical standpoint, has definite merit as a sludge conditioning process, the equipment capital costs, operating costs, and space requirements are appreciably greater for the freeze conditioning process than for the present chemical conditioning method.