title: Degradation studies of new substitutes for perfluorinated surfactants.
abstract: Perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS) are manmade, stable perfluorosurfactants. The properties of perfluoroalkylated compounds that cause them to persist in the environment are also the properties that made them attractive compounds for industrial usage for over 50 years. Due to the unique properties of the carbon-fluorine bond and the polarity of perfluoroalkyl groups, potential substitutes to replace perfluorinated surfactants in most cases continue to be perfluoroalkyl based. Thus, issues of persistence in the environment remain. There is a need to test emerging new substitute surfactants for biodegradability. This study involved degradability measurements of emerging perfluorinated surfactant substitutes. The stability of the substitutes of perfluorinated surfactants was tested by employing advanced oxidation processes, which were based on degradation by ultraviolet lamp, hydrogen peroxide, or both, followed by conventional tests, among them an automated method based on the manometric respirometry test (OECD 301 F; OxiTop), closed-bottle test (OECD 301 D), and standardized fixed-bed bioreactor on perfluorobutane sulfonate, fluorosurfactant Zonyl, two fluoraliphatic esters (NOVEC FC-4430 and NOVEC FC-4432), and 10-(trifluoromethoxy) decane 1 sulfonate. Most of these new surfactants are well established in the marketplace and have been used in several applications as alternatives to PFOS- and PFOA-based surfactants. Ready biodegradation tests for fluoroaliphatic esters, the fluorosurfactant Zonyl, perfluorobutane sulfonate, and 10-(trifluoromethoxy) decane-1-sulfonate using the manometric respirometry test (OxiTop) did not meet the ready biodegradability test criteria. However, 10-(trifluoromethoxy) decane-1-sulfonate was observed to be degradable when a standardized fixed-bed bioreactor test was applied.
authors.affiliation: Department of Chemistry, Pontifícia Universidade Católica do Rio de Janeiro, Gávea, RJ, Brazil. nquinete@aluno.puc-rio.br
authors.forename: Natalia
authors.initials: N
authors.lastname: Quinete
authors.forename: Francis
authors.initials: F
authors.lastname: Orata
authors.forename: Anke
authors.initials: A
authors.lastname: Maes
authors.forename: Markus
authors.initials: M
authors.lastname: Gehron
authors.forename: Karl-Heinz
authors.initials: KH
authors.lastname: Bauer
authors.forename: Isabel
authors.initials: I
authors.lastname: Moreira
authors.forename: Rolf-Dieter
authors.initials: RD
authors.lastname: Wilken
mesh_terms: D001673:Biodegradation, Environmental; D004785:Environmental Pollutants / Q000032:analysis / Q000737:chemistry*; D052918:Environmental Restoration and Remediation / Q000379:methods*; D005466:Fluorocarbons / Q000032:analysis / Q000737:chemistry*; D006861:Hydrogen Peroxide / Q000737:chemistry; D009930:Organic Chemicals / Q000032:analysis / Q000737:chemistry; D010084:Oxidation-Reduction; D013451:Sulfonic Acids / Q000032:analysis / Q000737:chemistry; D013501:Surface-Active Agents / Q000032:analysis / Q000737:chemistry*; D014466:Ultraviolet Rays
chemical_list: D004785:Environmental Pollutants; D005466:Fluorocarbons; D009930:Organic Chemicals; D013451:Sulfonic Acids; D013501:Surface-Active Agents; C542778:nonafluorobutane-1-sulfonic acid; C038646:Zonyl; D006861:Hydrogen Peroxide