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Freeze‐thaw residuals conditioning
Author(s) -
Parker Philip J.,
Collins Anthony G.,
DeWolfe James R.
Publication year - 2000
Publication title -
journal ‐ american water works association
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.466
H-Index - 74
eISSN - 1551-8833
pISSN - 0003-150X
DOI - 10.1002/j.1551-8833.2000.tb08931.x
Subject(s) - conditioning , curing (chemistry) , pulp and paper industry , environmental science , chemistry , waste management , materials science , mathematics , engineering , composite material , statistics
Freeze–thaw conditioning can reduce residuals disposal costs. Freeze–thaw conditioning is an effective way to process water treatment residuals. For many years the process has used natural out‐of‐doors freezing, but development of mechanical processes has been hindered by a lack of fundamental information about the process. This article presents the results of experiments performed to study the effects of initial solids content, curing time, and freezing rate on dewaterability of residuals from five water treatment facilities in the northeastern United States. Dewaterability of all residuals sharply increased following freeze–thaw conditioning. In the experimental procedure used, dewaterability following freezing and thawing was independent of rate. However, initial solids content and curing time strongly affected dewaterability, which was best for residuals frozen at high solids content and cured for long times. Cake solids contents > 40 percent w/w were achieved. Generally, the process was most successful for residuals that exhibited the best dewaterability before freeze–thaw conditioning. Finally, cost‐optimum freezing conditions were determined.