Method for degrading perfluorinated compound by photo-reduction defluorination

A compound and fluorine-based technology, which is applied in the field of photoreduction defluorination to degrade perfluorinated compounds, can solve the problems of inefficient defluorination of perfluorinated organic compounds, and achieve the effect of reducing product toxicity

Inactive Publication Date: 2010-11-17
TONGJI UNIV
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

However, the generated OH still cannot efficient

Method used

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  • Method for degrading perfluorinated compound by photo-reduction defluorination
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  • Method for degrading perfluorinated compound by photo-reduction defluorination

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Embodiment 1

[0029] Such as figure 1 As shown, 720mL containing 0.03mmol / L of perfluorooctanoic acid (PFOA) and 0.6mmol / L of potassium thiosulfate solution is placed in reactor 3, the emission wavelength of UV lamp 1 is adjusted to be 510nm, and the Under the irradiation of UV lamp 1 of 2, PFOA reacts with potassium thiosulfate to start defluorination, and the decomposition effect of defluorination is shown in figure 2 . The defluorination rate is directly calculated according to the fluoride ion concentration in the water during the reaction, and the fluoride ion concentration in the water is determined by ion chromatography. The case of adding reducing substances ( figure 2 marked as "reducing substances"), the fluoride ion concentration in the reaction solution increases with the reaction time, and the defluorination rate of PFOA reaches more than 80% after 8 hours of reaction, and the average PFOA molecule contains 15 fluorine (F) Twelve fluorines had fallen into solution.

Embodiment 2

[0031] 720mL containing 0.03mmol / L perfluorooctane sulfonic acid (PFOS) and potassium sulfite solution of 0.09mmol / L are placed in the reactor, and the emission wavelength of the ultraviolet lamp is adjusted to be 475nm. Under the irradiation of a 14W ultraviolet lamp, PFOS React with potassium sulfite to start defluorination, the defluorination decomposition effect can be seen image 3 . The defluorination rate is directly calculated according to the fluoride ion concentration in the water during the reaction, and the fluoride ion concentration in the water is determined by ion chromatography. The case of adding reducing substances ( figure 2 marked as "reducing substances"), the fluoride ion concentration in the reaction solution increases with the reaction time, and the defluorination rate of PFOS reaches more than 35.6% after 8 hours of reaction, and the average PFOS molecule contains 17 fluorine (F) 6.1 pieces of fluorine have fallen into solution.

Embodiment 3

[0033] Place 720mL of perfluorooctane sulfonic acid (PFOS) containing 0.03mmol / L and 0.15mmol / L potassium ferrocyanide solution in the reactor, adjust the emission wavelength of the ultraviolet lamp to 505nm, under the irradiation of a 14W ultraviolet lamp , PFOS reacts with potassium ferrocyanide to start defluorination. The defluorination rate is directly calculated according to the fluoride ion concentration in the water during the reaction, and the fluoride ion concentration in the water is determined by ion chromatography. The concentration of fluorine ions in the reaction solution increases with the reaction time. After 8 hours of reaction, the defluorination rate of PFOS reaches more than 30.4%, and 5.2 of the 17 fluorines (F) contained in the average PFOS molecule have dropped into the solution.

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Abstract

The invention relates to a method for degrading a perfluorinated compound by photo-reduction defluorination, which comprises the following steps of: putting the perfluorinated compound into a reaction container provided with an ultraviolet lamp, feeding a reductive substance into the reaction container through a feeding hole, performing ultraviolet irradiation through the ultraviolet lamp, and performing degradation and defluorination reaction on the perfluorinated compound and the reductive substance. Compared with the prior art, the method is simple and feasible, can be performed at normal temperature under normal pressure, does not need complex equipment, and has no requirement for the initial concentration of the perfluorinated compound; the perfluorinated compound with any concentration can be treated by adopting the method; and the toxicity of the decomposed product is reduced, and the decomposed product can be further treated by adopting other methods.

Description

technical field [0001] The invention relates to a reduction method, in particular to a photoreduction defluorination method for degrading perfluorinated compounds. Background technique [0002] Perfluorinated organic compounds (PFCs) refer to the general term for a class of organic compounds in which all hydrogen atoms (H) connected to carbon atoms (C) in the molecular structure of organic compounds are replaced by fluorine atoms (F), such as carbon tetrafluoride (CF 4 ), perfluorooctanoic acid (CF 3 -CF 2 -CF 2 -CF 2 -CF 2 -CF 2 -CF 2 -COOH) and PFOS (CF 3 -CF 2 -CF 2 -CF 2 -CF 2 -CF 2 -CF 2 -CF 2 -SO 3 h). Perfluorinated organic compounds have excellent properties such as chemical inertness and heat resistance, and have been widely used as surfactants, catalysts, lubricants, pesticides, and intermediates for synthetic drugs, fluororubbers, and resins since the 1950s. As hydrophobic and oleophobic synthetic surfactants with excellent performance, perfluoroo...

Claims

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Application Information

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IPC IPC(8): A62D3/176A62D3/37A62D101/28A62D101/22
Inventor 张超杰曲燕周琪李飞陈晶
Owner TONGJI UNIV
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