Virginia Tech
High-Intensity Shear as a Wet Sludge Disintegration Technology and a Mechanism for Floc Structure Analysis
Abstract
dc:description.abstractBy shearing activated sludge using a high shear rotor stator device, bioavailable proteinaceous material can be produced. Operation at elevated temperatures, serves to increase the amount of material that is rendered soluble (<0.45 um) and biodegradable. The storage of sludge under anoxic condition prior to shearing does not appear to enhance solublization of solids, though deflocculation and deterioration of dewaterablility was observed. Anaerobic digestibility appears to be enhanced by the addition of a high shear as shown by increases in gas production and volatile solids destruction. The dewatering properties of activated sludge, measured by capillary suction time, deteriorated with the addition of sheared solids, but reaeration resulted in near complete recovery. The role of iron and iron chemistry plays a critical role in the activated sludge. Iron apparently selectively removes protein, in particular material ranging in the 1.5 um to 30K size range. The addition of ferric iron was found to increase SVI and decrease zone-settling velocity, when added to reactors with mechanically disintegrated sludges. Similar trends were not observed in reactors dosed with ferrous iron. Preliminary results suggest that the ferric/ferrous redox chemistry may serve to enhance floc structure, as observed by increased settling velocity and shear resistance for sludges dosed with ferrous sulfate.
Degree
thesis:*- Name thesis:degree_name
- Master of Science
- Level thesis:degree_level
- masters
- Discipline thesis:degree_discipline
- Environmental Sciences and Engineering
- Department dc:contributor.department
- Environmental Sciences and Engineering
- Grantor dc:publisher
- Virginia Tech
- Year dc:date.issued
- 2001
Author and committee
dc:creator, dc:contributor.*- Author dc:creator
-
- Muller, Christopher D.
- Chair dc:contributor.committeechair
-
- Novak, John T.
- Committee members dc:contributor.committeemember
-
- Randall, Clifford W.
- Love, Nancy G.
Subjects
dc:subject × 5Rights
dc:rights- Statement dc:rights
-
- In Copyright
- Licence dc:rights.uri
Identifiers
dc:identifier.*- Dc Identifier Other
- etd-06192001-143911
- OAI identifier oai:identifier
- oai:vtechworks.lib.vt.edu:10919/33650