Dehydration of Flocs by Freezing
A conceptual model was developed to explain the freeze/thaw conditioning process. This process transforms difficult-to-dewater residuals into a slurry of granular particles (zots) from which water readily drains. The conceptual model states that the most important effect of freezing and thawing is the removal of surface water from the colloidal particles comprising the floc. In addition to creating a drier floc, this dehydration may also explain the irreversibility of the process:  dehydration causes the particles to come into close contact, at which point a new bond forms. Formation of a new bond explains the strength and granularity of the zots.