title: Retainment of the antimicrobial agent triclosan in a septic tank.
abstract: Laboratory experiments were conducted to investigate the fate of the antimicrobial agent triclosan (TCS) in a conventional septic tank. The main mechanism of TCS removal from wastewater was identified to be rapid TCS sorption to suspended particles followed by settling of these particles to the bottom of the septic tank. Sorption to particles was completed within minutes while the settling took several days. Therefore, in a septic tank the removal of TCS from wastewater is mainly determined by the removal of suspended particles by sedimentation. Over 5 days of hydraulic residence time the initial dissolved TCS concentration of 100 μg L(-1) was reduced by 87 ± 8%. During the first 24 hours, 66-86% of all removed TCS was retained, whereas during the remainder of the experiment a slight but steady decrease in TCS concentration was observed. This was most likely caused by TCS diffusion and its subsequent sorption onto the septic sludge.
authors.affiliation: Department of Water Management, Faculty of Environmental Engineering, Vilnius Gediminas Technical University, Sauletekio 11, LT-10223 Vilnius, Lithuania E-mail: ala.kirjanova@vgtu.lt.
authors.forename: Ala
authors.initials: A
authors.lastname: Kirjanova
authors.affiliation: Department of Water Management, Faculty of Environmental Engineering, Vilnius Gediminas Technical University, Sauletekio 11, LT-10223 Vilnius, Lithuania E-mail: ala.kirjanova@vgtu.lt.
authors.forename: Mindaugas
authors.initials: M
authors.lastname: Rimeika
authors.affiliation: Department of Civil Engineering, Faculty of Engineering and Science, Aalborg University, Sohngaardsholmsvej 57, 9000 Aalborg, Denmark.
authors.forename: Jes
authors.initials: J
authors.lastname: Vollertsen
authors.affiliation: Department of Civil Engineering, Faculty of Engineering and Science, Aalborg University, Sohngaardsholmsvej 57, 9000 Aalborg, Denmark.
authors.forename: Asbjørn Haaning
authors.initials: AH
authors.lastname: Nielsen
mesh_terms: D000891:Anti-Infective Agents, Local / Q000032:analysis*; D004784:Environmental Monitoring; D012722:Sewage / Q000032:analysis*; D014260:Triclosan / Q000032:analysis*; D014865:Waste Disposal, Fluid / Q000295:instrumentation; D014874:Water Pollutants, Chemical / Q000032:analysis*
chemical_list: D000891:Anti-Infective Agents, Local; D012722:Sewage; D014874:Water Pollutants, Chemical; D014260:Triclosan