Kinetic model for sonolytic degradation of non-volatile surfactants:Perfluoroalkyl substances
| Autor: | Rominder P.S. Suri, Gangadhar Andaluri, Takshak Shende |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2019 |
| Předmět: |
Sonochemical catalysis
Acoustics and Ultrasonics Diffusion PFAS 02 engineering and technology 010402 general chemistry 01 natural sciences Catalysis Inorganic Chemistry chemistry.chemical_compound Pulmonary surfactant PFOS Ultrasound Chemical Engineering (miscellaneous) Environmental Chemistry Radiology Nuclear Medicine and imaging Sulfate Hydrogen peroxide Chemistry Organic Chemistry PFOA 021001 nanoscience & nanotechnology 0104 chemical sciences Perfluoroalkyl substances Environmental chemistry Perfluorooctanoic acid Degradation (geology) 0210 nano-technology Fluoride |
| Zdroj: | Shende, T, Andaluri, G & Suri, R P S 2019, ' Kinetic model for sonolytic degradation of non-volatile surfactants : Perfluoroalkyl substances ', Ultrasonics Sonochemistry, vol. 51, pp. 359-368 . https://doi.org/10.1016/j.ultsonch.2018.08.028 |
| Popis: | Sonolytic degradation kinetics of non-volatile surfactant perfluorooctanoic acid (PFOA) and perfluorooctane sulfonic acid (PFOS) were investigated over a range of concentration, considering active cavity as a catalyst. The Michaelis-Menten type kinetic model was developed to empirically estimate the concentration of active cavity sites during reactions. Sonolytic degradation of PFOA and PFOS, as well as the formation of its inorganic constituents, fluoride, and sulfate, follows saturation kinetics of pseudo-first order at lower concentration (23.60 µM). Nitrate and hydrogen peroxide formations were 0.53 ± 0.14 µM/min and 0.95 ± 0.11 µM/min, respectively. At a power density of 77 W/L and frequency of 575 kHz, the empirically estimated maximum number of active cavity sites that could lead to the sonolytic reaction were 89.25 and 8.8 mM for PFOA and PFOS, respectively. This study suggests that a lower number of active cavity sites with higher temperature needed to degrade PFOS might be the reason for lower degradation rate of PFOS compared to that of PFOA. Diffusion of non-volatile surfactants at the cavity-water interface is found to be the rate-limiting step for the mineralization of perfluoroalkyl substances. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|