{"id":{"repo_id":"vt","oai_identifier":"oai:vtechworks.lib.vt.edu:10919/36295"},"canonical_url":"https://search.dev.ndltd.org/etd/vt/oai:vtechworks.lib.vt.edu:10919/36295","repository":{"repo_id":"vt","name":"Virginia Tech","base_url":"https://vtechworks.lib.vt.edu/oai/request"},"display":{"title":"Evaluation of Triclosan Reactivity in Monochloraminated Waters","abstract":"The antibacterial agent, triclosan, is widely used in many household personal care products, and it has recently been detected in wastewater treatment plant effluents and in source waters used for drinking water supply. Accordingly, the reactivity of triclosan with the disinfectants used in wastewater treatment and in the production of potable water is of interest. Monochloramine is used as an alternative disinfectant in drinking water treatment to minimize production of regulated disinfection by-products. This study examined the reactions between triclosan and monochloramine and involved analysis of monochloramine and triclosan decay and product formation under drinking water treatment conditions over a pH range of 6.5 to 10.5. Monochloramine decay in the presence of triclosan was measured relative to monochloramine auto-decomposition in the absence of triclosan using UV-VIS spectrophotometry. Experimental results showed that the monochloramine auto-decomposition intermediates, free chlorine and dichloramine, are responsible for a majority of the observed triclosan decay and product formation. A kinetic model for monochloramine auto-decomposition was modified to include terms and rate coefficients for the reactions of triclosan with monochloramine (<i>k</i> = 90.4 M<sup>-1</sup>h<sup>-1</sup>), free chlorine (<i>k</i> = 1.94&#215;10<sup>7</sup> M<sup>-1</sup>h<sup>-1</sup>), and dichloramine (<i>k</i> = 2&#215;10<sup>5</sup> M<sup>-1</sup>h<sup>-1</sup>), and was able to predict triclosan and monochloramine decay. It was determined that the reactions of dichloramine and free chlorine with triclosan were 10<sup>3</sup> and 10<sup>5</sup> times faster, respectively, than the reaction of monochloramine with triclosan. The products of these reactions, detected using GC-MS, included three chlorinated triclosan intermediates, 2,4-dichlorophenol, and 2,4,6-trichlorophenol. Low levels of chloroform were detected at pH values of 6.5 and 7.5.","abstract_html":"The antibacterial agent, triclosan, is widely used in many household personal care products, and it has recently been detected in wastewater treatment plant effluents and in source waters used for drinking water supply. Accordingly, the reactivity of triclosan with the disinfectants used in wastewater treatment and in the production of potable water is of interest. Monochloramine is used as an alternative disinfectant in drinking water treatment to minimize production of regulated disinfection by-products. This study examined the reactions between triclosan and monochloramine and involved analysis of monochloramine and triclosan decay and product formation under drinking water treatment conditions over a pH range of 6.5 to 10.5. Monochloramine decay in the presence of triclosan was measured relative to monochloramine auto-decomposition in the absence of triclosan using UV-VIS spectrophotometry. Experimental results showed that the monochloramine auto-decomposition intermediates, free chlorine and dichloramine, are responsible for a majority of the observed triclosan decay and product formation. A kinetic model for monochloramine auto-decomposition was modified to include terms and rate coefficients for the reactions of triclosan with monochloramine (&lt;i&gt;k&lt;/i&gt; = 90.4 M&lt;sup&gt;-1&lt;/sup&gt;h&lt;sup&gt;-1&lt;/sup&gt;), free chlorine (&lt;i&gt;k&lt;/i&gt; = 1.94&amp;#215;10&lt;sup&gt;7&lt;/sup&gt; M&lt;sup&gt;-1&lt;/sup&gt;h&lt;sup&gt;-1&lt;/sup&gt;), and dichloramine (&lt;i&gt;k&lt;/i&gt; = 2&amp;#215;10&lt;sup&gt;5&lt;/sup&gt; M&lt;sup&gt;-1&lt;/sup&gt;h&lt;sup&gt;-1&lt;/sup&gt;), and was able to predict triclosan and monochloramine decay. It was determined that the reactions of dichloramine and free chlorine with triclosan were 10&lt;sup&gt;3&lt;/sup&gt; and 10&lt;sup&gt;5&lt;/sup&gt; times faster, respectively, than the reaction of monochloramine with triclosan. The products of these reactions, detected using GC-MS, included three chlorinated triclosan intermediates, 2,4-dichlorophenol, and 2,4,6-trichlorophenol. Low levels of chloroform were detected at pH values of 6.5 and 7.5.","abstract_has_math":false,"creators":["Greyshock, Aimee E."],"institution":"Virginia Tech","degree_name":"Master of Science","degree_level":"masters","degree_discipline":"Environmental Planning","degree_department":"Environmental Engineering","school":null,"contributors":[],"advisors":[],"committee_chairs":["Vikesland, Peter J."],"committee_members":["Love, Nancy G.","Edwards, Marc A."],"year":2004,"date_issued":"2004-10-19","date_published":"2004-10-19","updated_at":"2026-07-22T22:19:13Z","subjects":["Disinfection By-Products","Drinking Water","Monochloramine","Triclosan"],"languages":[],"rights":["In Copyright"],"rights_urls":["http://rightsstatements.org/vocab/InC/1.0/"],"identifier_entries":[{"key":"dc:identifier.other","label":"Dc Identifier Other","values":["etd-12192004-122018"],"render_values":[{"text":"etd-12192004-122018","href":null,"code":true}]}]},"links":{"outbound_url":"http://hdl.handle.net/10919/36295","outbound_label":"Handle","outbound_source":"dc:identifier.uri"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor.committeechair","label":"Committee Chair","values":["Vikesland, Peter J."]},{"key":"dc:contributor.committeemember","label":"Committee Member","values":["Love, Nancy G.","Edwards, Marc A."]},{"key":"dc:contributor.department","label":"Department","values":["Environmental Engineering"]},{"key":"dc:creator","label":"Author","values":["Greyshock, Aimee E."]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date.accessioned","label":"Dc Date Accessioned","values":["2014-03-14T20:50:23Z"]},{"key":"dc:date.available","label":"Dc Date Available","values":["2014-03-14T20:50:23Z","2007-01-07"]},{"key":"dc:date.issued","label":"Date","values":["2004-10-19"]},{"key":"dc:publisher","label":"Institution","values":["Virginia Tech"]},{"key":"dc:type","label":"Dc Type","values":["Thesis"]},{"key":"thesis:degree_discipline","label":"Discipline","values":["Environmental Planning"]},{"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":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["Disinfection By-Products","Drinking Water","Monochloramine","Triclosan"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"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.other","label":"Dc Identifier Other","values":["etd-12192004-122018"]},{"key":"dc:identifier.uri","label":"Identifier URI","values":["http://hdl.handle.net/10919/36295"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description.abstract","label":"Abstract","values":["The antibacterial agent, triclosan, is widely used in many household personal care products, and it has recently been detected in wastewater treatment plant effluents and in source waters used for drinking water supply. Accordingly, the reactivity of triclosan with the disinfectants used in wastewater treatment and in the production of potable water is of interest. Monochloramine is used as an alternative disinfectant in drinking water treatment to minimize production of regulated disinfection by-products. This study examined the reactions between triclosan and monochloramine and involved analysis of monochloramine and triclosan decay and product formation under drinking water treatment conditions over a pH range of 6.5 to 10.5. Monochloramine decay in the presence of triclosan was measured relative to monochloramine auto-decomposition in the absence of triclosan using UV-VIS spectrophotometry. Experimental results showed that the monochloramine auto-decomposition intermediates, free chlorine and dichloramine, are responsible for a majority of the observed triclosan decay and product formation. A kinetic model for monochloramine auto-decomposition was modified to include terms and rate coefficients for the reactions of triclosan with monochloramine (<i>k</i> = 90.4 M<sup>-1</sup>h<sup>-1</sup>), free chlorine (<i>k</i> = 1.94&#215;10<sup>7</sup> M<sup>-1</sup>h<sup>-1</sup>), and dichloramine (<i>k</i> = 2&#215;10<sup>5</sup> M<sup>-1</sup>h<sup>-1</sup>), and was able to predict triclosan and monochloramine decay. It was determined that the reactions of dichloramine and free chlorine with triclosan were 10<sup>3</sup> and 10<sup>5</sup> times faster, respectively, than the reaction of monochloramine with triclosan. The products of these reactions, detected using GC-MS, included three chlorinated triclosan intermediates, 2,4-dichlorophenol, and 2,4,6-trichlorophenol. Low levels of chloroform were detected at pH values of 6.5 and 7.5."]},{"key":"dc:description.degree","label":"Dc Description Degree","values":["Master of Science"]},{"key":"dc:title","label":"Title","values":["Evaluation of Triclosan Reactivity in Monochloraminated Waters"]}]}],"canonical_facts":{"dc:contributor.committeechair":["Vikesland, Peter J."],"dc:contributor.committeemember":["Love, Nancy G.","Edwards, Marc A."],"dc:contributor.department":["Environmental Engineering"],"dc:creator":["Greyshock, Aimee E."],"dc:date.accessioned":["2014-03-14T20:50:23Z"],"dc:date.available":["2014-03-14T20:50:23Z","2007-01-07"],"dc:date.issued":["2004-10-19"],"dc:description.abstract":["The antibacterial agent, triclosan, is widely used in many household personal care products, and it has recently been detected in wastewater treatment plant effluents and in source waters used for drinking water supply. Accordingly, the reactivity of triclosan with the disinfectants used in wastewater treatment and in the production of potable water is of interest. Monochloramine is used as an alternative disinfectant in drinking water treatment to minimize production of regulated disinfection by-products. This study examined the reactions between triclosan and monochloramine and involved analysis of monochloramine and triclosan decay and product formation under drinking water treatment conditions over a pH range of 6.5 to 10.5. Monochloramine decay in the presence of triclosan was measured relative to monochloramine auto-decomposition in the absence of triclosan using UV-VIS spectrophotometry. Experimental results showed that the monochloramine auto-decomposition intermediates, free chlorine and dichloramine, are responsible for a majority of the observed triclosan decay and product formation. A kinetic model for monochloramine auto-decomposition was modified to include terms and rate coefficients for the reactions of triclosan with monochloramine (<i>k</i> = 90.4 M<sup>-1</sup>h<sup>-1</sup>), free chlorine (<i>k</i> = 1.94&#215;10<sup>7</sup> M<sup>-1</sup>h<sup>-1</sup>), and dichloramine (<i>k</i> = 2&#215;10<sup>5</sup> M<sup>-1</sup>h<sup>-1</sup>), and was able to predict triclosan and monochloramine decay. It was determined that the reactions of dichloramine and free chlorine with triclosan were 10<sup>3</sup> and 10<sup>5</sup> times faster, respectively, than the reaction of monochloramine with triclosan. The products of these reactions, detected using GC-MS, included three chlorinated triclosan intermediates, 2,4-dichlorophenol, and 2,4,6-trichlorophenol. Low levels of chloroform were detected at pH values of 6.5 and 7.5."],"dc:description.degree":["Master of Science"],"dc:identifier.other":["etd-12192004-122018"],"dc:identifier.uri":["http://hdl.handle.net/10919/36295"],"dc:publisher":["Virginia Tech"],"dc:rights":["In Copyright"],"dc:rights.uri":["http://rightsstatements.org/vocab/InC/1.0/"],"dc:subject":["Disinfection By-Products","Drinking Water","Monochloramine","Triclosan"],"dc:title":["Evaluation of Triclosan Reactivity in Monochloraminated Waters"],"dc:type":["Thesis"],"thesis:degree_discipline":["Environmental Planning"],"thesis:degree_level":["masters"],"thesis:degree_name":["Master of Science"],"thesis:institution_name":["Virginia Polytechnic Institute and State University"]},"updated_at":"2026-07-22T22:19:13Z"}