Please use this identifier to cite or link to this item:
https://hdl.handle.net/11681/9236
Title: | A device for mechanical freeze-thaw conditioning of alum sludge |
Authors: | Martel, Courtland James Affleck, Rosa T. Yushak, Melinda L. |
Keywords: | Alum Water purification Freeze–thaw conditioning Water treatment plants Sludge disposal Sewage sludge |
Publisher: | Cold Regions Research and Engineering Laboratory (U.S.) Engineer Research and Development Center (U.S.) |
Series/Report no.: | CRREL Report ; 96-15. |
Description: | CRREL Report Abstract: This report contains the results of a study to develop a mechanical device for dewatering alum sludge by freeze–thaw. This proposed device is a combination of two conventional unit operations: a vacuum filter and a blast freezer. Bench-scale studies were conducted to evaluate this concept and develop preliminary design criteria. The results of filter leaf tests indicate that a suitable sludge layer could be collected on a cloth medium at a vacuum level of only 100 mm of Hg and a 5.0-minute filtration time. The volume of sludge was reduced by 67%. The freezing tests indicated that low freezing rate and a high initial solids content had a tendency to produce large alum sludge particles. However, fast freezing rates could be achieved without reducing the effective grain size below that of a fine sand. Curing time had no effect on grain size. The electrical cost of freezing sludge with this device was estimated to be $0.004/m^3, which is not expensive in relation to the total cost of water treatment which is approximately $0.25 to $0.50/m^3. |
Rights: | Approved for public release; distribution is unlimited. |
URI: | http://hdl.handle.net/11681/9236 |
Appears in Collections: | CRREL Report |
Files in This Item:
File | Description | Size | Format | |
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CR-96-15.pdf | 1.78 MB | Adobe PDF | View/Open |