Comparison of dewatering characteristics of chemically conditioned sludge and freeze/thawed sludge
The objective of this study was to compare dewatering properties of chemically conditioned sludge and freeze/thawed sludge as determined by mainly specific resistance to filtration (SRF), dry solids content of sludge cake (DS), and capillary suction time (CST) parameters. The experimental studies we...
Main Authors: | , |
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Format: | Article |
Language: | English |
Published: |
Pamukkale University
2018-12-01
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Series: | Pamukkale University Journal of Engineering Sciences |
Subjects: | |
Online Access: | https://dergipark.org.tr/tr/pub/pajes/issue/40976/498460 |
Summary: | The
objective of this study was to compare dewatering properties of chemically
conditioned sludge and freeze/thawed sludge as determined by mainly specific
resistance to filtration (SRF), dry solids content of sludge cake (DS), and
capillary suction time (CST) parameters. The experimental studies were carried
out with mixed sludge samples taken from a municipal wastewater treatment plant
in Turkey. In chemical conditioning experiments, sludge samples were
conditioned with different dosages of polymer using classical jar test method.
In freeze/thaw conditioning experiments, samples were frozen at -16.5 °C at
different freezing rates and then thawed at 21±1 °C at different times in order
to determine the effect of thawing time on dewatering performance. 25 mg/L
polymer dose and 2.71 mm/h freezing rate were found to be optimum in terms of
sludge conditioning. Rapid freezing that is higher than 8.13 mm/h could not
sufficiently condition the sludge and there was no significant effect of
thawing time on conditioning performance. Dewatering properties of chemically
conditioned sludge and freeze/thawed sludge was determined as very close to
each other. While CST and SRF reductions were calculated as 76% and 75%,
respectively at 25 mg/L polymer dosage, 2.71 mm/h freezing rate application
caused 79% and 76% reduction in CST and SRF, respectively. |
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ISSN: | 1300-7009 2147-5881 |