{"id":{"repo_id":"vt","oai_identifier":"oai:vtechworks.lib.vt.edu:10919/113490"},"canonical_url":"https://search.dev.ndltd.org/etd/vt/oai:vtechworks.lib.vt.edu:10919/113490","repository":{"repo_id":"vt","name":"Virginia Tech","base_url":"https://vtechworks.lib.vt.edu/oai/request"},"display":{"title":"Effect of phosphorus limiting conditions on process performance in activated sludge","abstract":"The effect of phosphorus limiting conditions on process performance was investigated using laboratory scale activated sludge units. Data were collected for COD:P ratios of 287:1, 212:1, 87:1 and 56:1 at several mean cell residence times. Data collected at COD:P ratios of 287:1 and 212:1 produced sludge with extremely poor settling characteristics and data were collected for only one mean cell residence time at each ratio; Data for COD:P ratios of 87:1 and 56:1 were used to estimate kinetic coefficients. These kinetic coefficients were used to develop predicted values of process performance subject to phosphorus limiting conditions utilizing mathematical and stoichiometric relationships. Predicted values were compared to laboratory data. For both predicted values and laboratory data, a phosphorus limitation resulted in decreased COD removal efficiency, nearly 100 percent phosphorus removal efficiency, decreased reactor solids concentrations, solids with poor settling characteristics, decreased sludge production and artificially high F/M ratios.","abstract_html":"The effect of phosphorus limiting conditions on process performance was investigated using laboratory scale activated sludge units. Data were collected for COD:P ratios of 287:1, 212:1, 87:1 and 56:1 at several mean cell residence times. Data collected at COD:P ratios of 287:1 and 212:1 produced sludge with extremely poor settling characteristics and data were collected for only one mean cell residence time at each ratio; Data for COD:P ratios of 87:1 and 56:1 were used to estimate kinetic coefficients. These kinetic coefficients were used to develop predicted values of process performance subject to phosphorus limiting conditions utilizing mathematical and stoichiometric relationships. Predicted values were compared to laboratory data. For both predicted values and laboratory data, a phosphorus limitation resulted in decreased COD removal efficiency, nearly 100 percent phosphorus removal efficiency, decreased reactor solids concentrations, solids with poor settling characteristics, decreased sludge production and artificially high F/M ratios.","abstract_has_math":false,"creators":["Hawkins, James M. (James Meade)"],"institution":"Virginia Polytechnic Institute and State University","degree_name":"M.S.","degree_level":"masters","degree_discipline":"Sanitary Engineering","degree_department":"Sanitary Engineering","school":null,"contributors":[],"advisors":[],"committee_chairs":[],"committee_members":[],"year":1983,"date_issued":"1983","date_published":"1983","updated_at":"2026-07-22T22:20:21Z","subjects":[],"languages":["en"],"rights":["In Copyright"],"rights_urls":["http://rightsstatements.org/vocab/InC/1.0/"],"identifier_entries":[]},"links":{"outbound_url":"http://hdl.handle.net/10919/113490","outbound_label":"Handle","outbound_source":"dc:identifier.uri"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor.department","label":"Department","values":["Sanitary Engineering"]},{"key":"dc:creator","label":"Author","values":["Hawkins, James M. (James Meade)"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date.accessioned","label":"Dc Date Accessioned","values":["2023-01-27T04:47:47Z"]},{"key":"dc:date.available","label":"Dc Date Available","values":["2023-01-27T04:47:47Z"]},{"key":"dc:date.issued","label":"Date","values":["1983"]},{"key":"dc:publisher","label":"Institution","values":["Virginia Polytechnic Institute and State University"]},{"key":"dc:type","label":"Dc Type","values":["Thesis"]},{"key":"dc:type.dcmitype","label":"Dc Type Dcmitype","values":["Text"]},{"key":"thesis:degree_discipline","label":"Discipline","values":["Sanitary Engineering"]},{"key":"thesis:degree_level","label":"Degree Level","values":["masters"]},{"key":"thesis:degree_name","label":"Degree Name","values":["M.S."]},{"key":"thesis:institution_name","label":"Thesis Institution Name","values":["Virginia Polytechnic Institute and State University"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:language.iso","label":"Language (ISO)","values":["en"]},{"key":"dc:rights","label":"Dc Rights","values":["In Copyright"]},{"key":"dc:rights.uri","label":"Rights URI","values":["http://rightsstatements.org/vocab/InC/1.0/"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier.uri","label":"Identifier URI","values":["http://hdl.handle.net/10919/113490"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description.abstract","label":"Abstract","values":["The effect of phosphorus limiting conditions on process performance was investigated using laboratory scale activated sludge units. Data were collected for COD:P ratios of 287:1, 212:1, 87:1 and 56:1 at several mean cell residence times. Data collected at COD:P ratios of 287:1 and 212:1 produced sludge with extremely poor settling characteristics and data were collected for only one mean cell residence time at each ratio; Data for COD:P ratios of 87:1 and 56:1 were used to estimate kinetic coefficients. These kinetic coefficients were used to develop predicted values of process performance subject to phosphorus limiting conditions utilizing mathematical and stoichiometric relationships. Predicted values were compared to laboratory data. For both predicted values and laboratory data, a phosphorus limitation resulted in decreased COD removal efficiency, nearly 100 percent phosphorus removal efficiency, decreased reactor solids concentrations, solids with poor settling characteristics, decreased sludge production and artificially high F/M ratios."]},{"key":"dc:description.degree","label":"Dc Description Degree","values":["M.S."]},{"key":"dc:format.mimetype","label":"Dc Format Mimetype","values":["application/pdf"]},{"key":"dc:title","label":"Title","values":["Effect of phosphorus limiting conditions on process performance in activated sludge"]}]}],"canonical_facts":{"dc:contributor.department":["Sanitary Engineering"],"dc:creator":["Hawkins, James M. (James Meade)"],"dc:date.accessioned":["2023-01-27T04:47:47Z"],"dc:date.available":["2023-01-27T04:47:47Z"],"dc:date.issued":["1983"],"dc:description.abstract":["The effect of phosphorus limiting conditions on process performance was investigated using laboratory scale activated sludge units. Data were collected for COD:P ratios of 287:1, 212:1, 87:1 and 56:1 at several mean cell residence times. Data collected at COD:P ratios of 287:1 and 212:1 produced sludge with extremely poor settling characteristics and data were collected for only one mean cell residence time at each ratio; Data for COD:P ratios of 87:1 and 56:1 were used to estimate kinetic coefficients. These kinetic coefficients were used to develop predicted values of process performance subject to phosphorus limiting conditions utilizing mathematical and stoichiometric relationships. Predicted values were compared to laboratory data. For both predicted values and laboratory data, a phosphorus limitation resulted in decreased COD removal efficiency, nearly 100 percent phosphorus removal efficiency, decreased reactor solids concentrations, solids with poor settling characteristics, decreased sludge production and artificially high F/M ratios."],"dc:description.degree":["M.S."],"dc:format.mimetype":["application/pdf"],"dc:identifier.uri":["http://hdl.handle.net/10919/113490"],"dc:language.iso":["en"],"dc:publisher":["Virginia Polytechnic Institute and State University"],"dc:rights":["In Copyright"],"dc:rights.uri":["http://rightsstatements.org/vocab/InC/1.0/"],"dc:title":["Effect of phosphorus limiting conditions on process performance in activated sludge"],"dc:type":["Thesis"],"dc:type.dcmitype":["Text"],"thesis:degree_discipline":["Sanitary Engineering"],"thesis:degree_level":["masters"],"thesis:degree_name":["M.S."],"thesis:institution_name":["Virginia Polytechnic Institute and State University"]},"updated_at":"2026-07-22T22:20:21Z"}