| Article ID | Journal | Published Year | Pages | File Type |
|---|---|---|---|---|
| 168138 | Chinese Journal of Chemical Engineering | 2015 | 7 Pages |
A novel thermal-assisted ultra-violet (UV) photocatalysis digestion method for the determination of total phosphorus (TP) in water samples was introduced in this work. The photocatalytic experiments for TP digestion were conducted using a 365 nm wavelength UV light and TiO2 particles as the photocatalyst. Sodium tripolyphosphate and sodium glycerophosphate were used as the typical components of TP and the digested samples were then determined by spectrophotometry after phosphomolybdenum blue reaction. The effects of operational parameters such as reaction time and temperature were studied for the digestion of TP and the kinetic analysis of two typical components was performed in this paper. The pseudo-first-order rate constants k of two phosphorus compounds at different temperatures were obtained and the Arrhenius equation was employed to explain the effect of temperature on rate constant k. Compared with the conventional thermal digestion method for TP detection, it was found that the temperature was decreased from 120 °C to 60 °C with same conversion rate and time in this thermal-assisted UV digestion method, which enabled the digestion process work at normal pressure. Compared with the individual ultra-violet (UV) photocatalysis process, the digestion time was also decreased from several hours to half an hour using the thermal-assisted UV digestion method. This method will not lead to secondary pollution since no oxidant was needed in the thermal-assisted UV photocatalysis digestion process, which made it more compatible with electrochemical detection of TP.
Graphical abstractIn this paper, a novel oxidant-free thermal-assisted ultra-violet (UV) photocatalysis oxidation method for total phosphorus (TP) digestion is proposed. In this digestion process, the digestion efficiency increases with the elevation of the temperature. The thermal-assisted photocatalysis digestion approximately follows the pseudo-first order rate kinetics model. And relationship between rate constant and temperature could be described by the Arrhenius equation. Compared with the conventional thermal digestion method for TP detection, this thermal-assisted UV digestion method decreases the temperature from 120 °C to 60 °C with same conversion rate and time, which enables the digestion process work at normal pressure. This method cannot lead to secondary pollution since no oxidant is needed in the thermal-assisted UV photocatalysis digestion process, which makes it more compatible with electrochemical detection of TP.Figure optionsDownload full-size imageDownload as PowerPoint slide
