In-situ online electrochemical-spectroscopy monitoring device for ion exchange membrane pollution in electrodialysis desalination process

Abstract

The invention discloses an in-situ online electrochemical-spectroscopy monitoring device for ion exchange membrane pollution in an electrodialysis desalination process. The in-situ online electrochemical-spectroscopy monitoring device mainly consists of three separation tanks, i.e., a left tank, a middle tank and a right tank, wherein inner walls of the three separation tanks are hollow, a hollowquartz optical window is embedded in the left tank, and a spectrum probe is arranged in the quartz optical window; the left tank is internally provided with a sheet electrode with a hollowed middle part, the quartz optical window passes through the sheet electrode to reach a position close to the membrane surface, and the outer walls of the left tank and the right tank are provided with light shielding sheets which can be disassembled; the inner part of the right tank and the inner part of the left tank are completely the same and are bilaterally symmetrical by taking the middle tank as a center; a platinum wire electrode is respectively penetrated above the quartz optical windows in the three separation tanks and used as a reference electrode; an anion exchange membrane is arranged between the left tank and the middle tank, and a cation exchange membrane is arranged between the middle tank and the right tank. The in-situ online electrochemical-spectroscopy monitoring device can monitor the pollution condition of the specific pollutants to the ion exchange membrane through a spectrometer, and simultaneously monitor the impedance change of each interface of the membrane through an electrochemical impedance spectrum.

Description

technical field [0001] The invention relates to the technical field of ion-exchange membrane mass transfer and membrane pollution monitoring, and more specifically relates to an in-situ electrochemical-spectroscopy monitoring device and method for ion-exchange membrane pollution in an electrodialysis desalination process. Background technique [0002] Electrodialysis, as an electrochemical technique that uses an electric field as the driving force to separate charged ions through an ion-exchange membrane, is not only used for the desalination of fresh brine and seawater, but also for the recovery of acid / alkali industrial wastewater and the removal of bromate from natural water . Due to the high chemical stability, low electrical resistance and good mechanical strength of ion exchange membranes (IEMs), electrodialysis (ED) can be applied in food and fermentation industry, medical supplies and acid-base recovery, and separation of inorganic salts from other fractions and org...

AI Technical Summary

Problems solved by technology

On-line methods only illustrate the occurrence of membrane fouling by measuring the transmembrane potential, voltage and ion flux. However, the comparative analysis of these macroscopic data cannot clarify the degree of membrane interface fouling and explain the mechanism of membrane fouling.

Off-line methods usually use microscopic characterization methods such as scanning electron microscopy, infrared spectroscopy, and atomic force microscopy, as well as electrochemical methods such as ex-situ electrochemical impedance spectroscopy. layer, the membrane can no longer be used after observation, and the membrane fouling process cannot be monitored online, and the membrane fouling behavior cannot be monitored in real time

In the electrodialysis system, membrane fouling includes the pollution of organic pollutants on the anion exchange membrane and the fouling of the cation ion exchange membrane caused by the scaling of inorganic substances on the surface of the cation exchange membrane. Membrane fouling

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