These fluorinated surfactants have no obvious cytotoxicity. However, there is still lack of information for the degradation mechanism and the test for wastewater treatment. The removal efficiency of PFOA is not significantly affected by H+, while high pH condition inhibit the degradation process. Download : Download high-res image (242KB)Download : Download full-size image. Effects of different variables on photodestruction of perfluorooctanoic acid in self-assembled micelle system. Perfluoroalkyl and polyfluoroalkyl substances (PFASs) are a class of highly persistent contaminants with high bioaccumulation and toxicity. Nonionic urethane fluorinated surfactants with double short fluoroalkyl chains were synthesized. ScienceDirect ® is a registered trademark of Elsevier B.V. ScienceDirect ® is a registered trademark of Elsevier B.V. Perfluorooctanoic acid (PFOA), surfactant used to make fluoropolymers such as Teflon; Perfluorononanoic acid (PFNA), surfactant in the emulsion polymerization of fluoropolymers, like PFOA. We use cookies to help provide and enhance our service and tailor content and ads. We use cookies to help provide and enhance our service and tailor content and ads. Download : Download high-res image (392KB)Download : Download full-size image. © 2019 Elsevier Ltd. All rights reserved. However, low surface activity, poor water solubility and complex preparation process of most currently reported alternatives restrict their widespread applications. Both configurations of self-assembled micelles and PFOA removal efficiencies are controlled by cationic surfactants. Using their reported surface-tension data, K i values of 0.00016 and 0.0023 cm are obtained for PFOA alone and with PFOS, respectively, a 14X increase.
These fluorinated surfactants show favorable wetting and emulsifying properties. HDTMA and PVPcoS modified montmorillonites were studied for treating PFOA wastewater. The initial concentrations of PFOA, IAA and cationic surfactant were 10 mg L −1, 1 mM, and 0.14 mM, respectively. The mixed modified montmorillonite system showed superior reactivity even for actual industrial wastewater. While in poly-4-vinylpyridine-co-styrene (PVPcoS)-modified montmorillonite, due to the multiple charges of PVPcoS, a flat conformation parallel to clay surface was expected. Copyright © 2020 Elsevier B.V. or its licensors or contributors. © 2019 Elsevier B.V. All rights reserved.
These fluorinated surfactants showed good salt and pH resistance. ScienceDirect ® is a registered trademark of Elsevier B.V. ScienceDirect ® is a registered trademark of Elsevier B.V. In addition, this product can provide stain and dirt pick up resistance by making the coating surface oleophobic. Our results also indicated that in the presence of high concentration of NaCl, the electrostatic attraction between Cl− and the positively charged micelle made the micelle structure loose and thus slightly reduced the degradation efficiency.
In this study, using perfluorooctanoic acid (PFOA) as the model pollutant, we further investigated the effects of different variables on the degradation processes. The RfD is an estimate of the daily exposure level that is likely to