{"id":{"repo_id":"vt","oai_identifier":"oai:vtechworks.lib.vt.edu:10919/64115"},"canonical_url":"https://search.dev.ndltd.org/etd/vt/oai:vtechworks.lib.vt.edu:10919/64115","repository":{"repo_id":"vt","name":"Virginia Tech","base_url":"https://vtechworks.lib.vt.edu/oai/request"},"display":{"title":"A study of a modified membrane filter technique for the enumeration of stressed fecal coliforms in urban runoff","abstract":"Urban runoff samples collected from a parking lot in Blacksburg, Virginia were analyzed by several techniques for fecal coliform recovery. The samples were also analyzed for heavy metal concentrations. Statistical analyses of data by the paired-t test showed that the standard membrane filter technique (MF) yielded significantly lower recoveries (0. 05 level) than the standard MPN procedure. A modified membrane filter technique employing a two-layer agar and a two hour 35°C preincubation period (M-2hr) was found to yield recoveries consistently greater (0.01 level) than the standard MF technique. Increasing the preincubation period to five hours in this modified method (M-5hr) resulted in recoveries that were even greater (0.005 level). The recoveries of the M-5hr method were found to closely approximate the MPN recoveries in most cases. It was concluded that a substantial percentage of the fecal coliform population found in urban runoff may be injured by a host of environmental factors, though no correlations could be made with metal concentrations or elapsed time between rainfalls. The M-5hr method was concluded to be quite useful in the recovery of these stressed organisms. though growth of non-fecal-coliforms was increased and made enumeration of the fecal coliforms more difficult.","abstract_html":"Urban runoff samples collected from a parking lot in Blacksburg, Virginia were analyzed by several techniques for fecal coliform recovery. The samples were also analyzed for heavy metal concentrations. Statistical analyses of data by the paired-t test showed that the standard membrane filter technique (MF) yielded significantly lower recoveries (0. 05 level) than the standard MPN procedure. A modified membrane filter technique employing a two-layer agar and a two hour 35°C preincubation period (M-2hr) was found to yield recoveries consistently greater (0.01 level) than the standard MF technique. Increasing the preincubation period to five hours in this modified method (M-5hr) resulted in recoveries that were even greater (0.005 level). The recoveries of the M-5hr method were found to closely approximate the MPN recoveries in most cases. It was concluded that a substantial percentage of the fecal coliform population found in urban runoff may be injured by a host of environmental factors, though no correlations could be made with metal concentrations or elapsed time between rainfalls. The M-5hr method was concluded to be quite useful in the recovery of these stressed organisms. though growth of non-fecal-coliforms was increased and made enumeration of the fecal coliforms more difficult.","abstract_has_math":false,"creators":["Brown, Edward Ryland"],"institution":"Virginia Polytechnic Institute and State University","degree_name":"Master of Science","degree_level":"masters","degree_discipline":"Environmental Sciences and Engineering","degree_department":"Environmental Sciences and Engineering","school":null,"contributors":[],"advisors":[],"committee_chairs":[],"committee_members":[],"year":1977,"date_issued":"1977","date_published":"1977","updated_at":"2026-07-22T22:19:45Z","subjects":[],"languages":["en"],"rights":["In Copyright"],"rights_urls":["http://rightsstatements.org/vocab/InC/1.0/"],"identifier_entries":[]},"links":{"outbound_url":"http://hdl.handle.net/10919/64115","outbound_label":"Handle","outbound_source":"dc:identifier.uri"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor.department","label":"Department","values":["Environmental Sciences and Engineering"]},{"key":"dc:creator","label":"Author","values":["Brown, Edward Ryland"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date.accessioned","label":"Dc Date Accessioned","values":["2015-11-13T20:44:43Z"]},{"key":"dc:date.available","label":"Dc Date Available","values":["2015-11-13T20:44:43Z"]},{"key":"dc:date.issued","label":"Date","values":["1977"]},{"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":["Environmental Sciences and Engineering"]},{"key":"thesis:degree_level","label":"Degree Level","values":["masters"]},{"key":"thesis:degree_name","label":"Degree Name","values":["Master of Science"]},{"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/10919/64115"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description.abstract","label":"Abstract","values":["Urban runoff samples collected from a parking lot in Blacksburg, Virginia were analyzed by several techniques for fecal coliform recovery. The samples were also analyzed for heavy metal concentrations. Statistical analyses of data by the paired-t test showed that the standard membrane filter technique (MF) yielded significantly lower recoveries (0. 05 level) than the standard MPN procedure. A modified membrane filter technique employing a two-layer agar and a two hour 35°C preincubation period (M-2hr) was found to yield recoveries consistently greater (0.01 level) than the standard MF technique. Increasing the preincubation period to five hours in this modified method (M-5hr) resulted in recoveries that were even greater (0.005 level). The recoveries of the M-5hr method were found to closely approximate the MPN recoveries in most cases. It was concluded that a substantial percentage of the fecal coliform population found in urban runoff may be injured by a host of environmental factors, though no correlations could be made with metal concentrations or elapsed time between rainfalls. The M-5hr method was concluded to be quite useful in the recovery of these stressed organisms. though growth of non-fecal-coliforms was increased and made enumeration of the fecal coliforms more difficult."]},{"key":"dc:description.degree","label":"Dc Description Degree","values":["Master of Science"]},{"key":"dc:format.mimetype","label":"Dc Format Mimetype","values":["application/pdf"]},{"key":"dc:title","label":"Title","values":["A study of a modified membrane filter technique for the enumeration of stressed fecal coliforms in urban runoff"]}]}],"canonical_facts":{"dc:contributor.department":["Environmental Sciences and Engineering"],"dc:creator":["Brown, Edward Ryland"],"dc:date.accessioned":["2015-11-13T20:44:43Z"],"dc:date.available":["2015-11-13T20:44:43Z"],"dc:date.issued":["1977"],"dc:description.abstract":["Urban runoff samples collected from a parking lot in Blacksburg, Virginia were analyzed by several techniques for fecal coliform recovery. The samples were also analyzed for heavy metal concentrations. Statistical analyses of data by the paired-t test showed that the standard membrane filter technique (MF) yielded significantly lower recoveries (0. 05 level) than the standard MPN procedure. A modified membrane filter technique employing a two-layer agar and a two hour 35°C preincubation period (M-2hr) was found to yield recoveries consistently greater (0.01 level) than the standard MF technique. Increasing the preincubation period to five hours in this modified method (M-5hr) resulted in recoveries that were even greater (0.005 level). The recoveries of the M-5hr method were found to closely approximate the MPN recoveries in most cases. It was concluded that a substantial percentage of the fecal coliform population found in urban runoff may be injured by a host of environmental factors, though no correlations could be made with metal concentrations or elapsed time between rainfalls. The M-5hr method was concluded to be quite useful in the recovery of these stressed organisms. though growth of non-fecal-coliforms was increased and made enumeration of the fecal coliforms more difficult."],"dc:description.degree":["Master of Science"],"dc:format.mimetype":["application/pdf"],"dc:identifier.uri":["http://hdl.handle.net/10919/64115"],"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":["A study of a modified membrane filter technique for the enumeration of stressed fecal coliforms in urban runoff"],"dc:type":["Thesis"],"dc:type.dcmitype":["Text"],"thesis:degree_discipline":["Environmental Sciences and Engineering"],"thesis:degree_level":["masters"],"thesis:degree_name":["Master of Science"],"thesis:institution_name":["Virginia Polytechnic Institute and State University"]},"updated_at":"2026-07-22T22:19:45Z"}