Comparative phosphorus removals using modified activated sludge processes

The operation of three continuous flow units as modified activated sludge models using mean cell residence time as a principal operational parameter has led to the following conclusions: 1. Lower mean cell residence times result in higher phosphorus removal efficiencies in biological reactors. 2. Higher mean solids residence times result in higher phosphorus removal efficiencies in strictly chemical reactors. 3. Calcium-phosphate precipitation can occur in continuous flow reactors in a normal activated sludge pH range (7.5-8.5) given sufficient Ca++ concentrations. 4. Calcium-phosphate precipitation can occur in the activated sludge process without hindering COO removal efficiency. 5. The phosphorus sludge content only exceeded the one to two percent range in the biochemical and chemical units, where phosphorus precipitation was the predominate phosphorus removal mechanism. 6. The anaerobiosis and acid stripping procedure, as used in this investigation, is not effective in enhancing either a biological or chemical unit's ability to remove phosphorus.

Name thesis:degree_name

Master of Science

Level thesis:degree_level

masters

Discipline thesis:degree_discipline

Civil Engineering

Department dc:contributor.department

Civil Engineering

Grantor dc:publisher

Virginia Tech

Year dc:date.issued

1977

Author dc:creator

• Elliott, William Richard

Chair dc:contributor.committeechair

• Sherrard, Joseph H.

Committee members dc:contributor.committeemember

• Randall, Clifford W.
• Boardman, Gregory D.

Statement dc:rights

• In Copyright

Licence dc:rights.uri

• http://rightsstatements.org/vocab/InC/1.0/

Dc Identifier Other

etd-06082010-020432

OAI identifier oai:identifier

oai:vtechworks.lib.vt.edu:10919/42947