Advanced reduction method and device for rapidly removing perfluoro-compounds from water

Abstract

The invention relates to the technical field of water treatment and particularly relates to an advanced reduction method and device for rapidly removing perfluoro-compounds from water. The method comprises the following steps: adding sodium sulfite into wastewater to be treated; putting the sodium sulfite added wastewater into a magnetic stirrer, starting to carry out stirring, and stably maintaining the stirring for 15 minutes in a dark place; putting the stirred wastewater into an inert quartz reaction vessel, opening a slide damper, carrying out high-strength ultraviolet-light source irradiation on the wastewater to be treated, starting to carry out timing, closing the slide damper until selected reaction time reaches, stopping irradiation, and carrying out sampling; determining the PFOA (Perfluorooctanoic Acid) / PFOS (Perfluorooctane sulfonates) concentration of a sample by using a liquid chromatogram-triple quadrupole mass spectrometer, determining fluorine ion concentration by using a fluoride-ion electrode, and calculating a defluorination ratio. According to the method and the device, efficient degradation and defluorination for PFOA / PFOS can be achieved under mild conditions, a photocatalyst is not required to be added during reaction, the cost is reduced, the reaction is rapid, final products are F<->, SO4<2-> and partial fluorinated olefins or alkanes, no secondary pollution is caused, and the aims of high efficiency and low consumption are truly achieved.

Description

technical field [0001] The present invention relates to the technical field of water treatment, in particular to an advanced reduction method and method for rapidly removing refractory organic matter-perfluorinated compounds (PFOA, PFOS) in industrial wastewater based on a high-strength ultraviolet-sulfite system. The device specifically relates to a process for removing PFOX (X is A or S) by combining high-intensity ultraviolet light and sulfite reduction. Background technique [0002] Due to their excellent physical and chemical properties such as high surface activity, thermal stability, and chemical stability, perfluorinated compounds have been widely used in the production of various substances such as emulsifiers, waterproof materials, metal surface protective coatings, and foam fire extinguishing agents. Among them, perfluorooctanoic acid (PFOA) and perfluorooctane sulfonic acid (PFOS) are the two most common types of perfluorinated compounds, which have been detected...

AI Technical Summary

Problems solved by technology

[0003] Due to the influence of electron-withdrawing groups (-CF2-) and the high bond energy of C-F (116KJ / mol), oxidation methods based on free radicals such as OH (including direct photolysis, photochemical oxidation, photocatalytic oxidation, etc.) cannot Effectively remove PFOA and PFOS, and most of these reactions need to be carried out under high temperature, high pressure and strong acid conditions. This kind of reaction also has the disadvantages of long processing time and low defluorination efficiency

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