OPTIMISATION OF A PHOTOCHEMICAL SENSOR FOR TOTAL ORGANIC CARBON MEASUREMENT

摘要

A new tool for the measurement of TOC based on the heterogeneous photocatalysis activated by two different light sources has o been planned.The instrument is constituted by a cell where the degradation occurs thanks to both the UV irradiation and the presence of a powered catalyst and by a measurement cell lodging CO_2 gas permeable membrane electrode (detector),thermometer,inlet and outlet ways for the samples.One of the sources has a maximum emission at 254nm,while the other simulates the solar spectrum.A suspension (1 g/L) of titanium dioxide (Degussa P25) has been used to catalyse the process.A magnetic stirrer and a circulating pump avoid the deposition of the catalyst on the bottom of the reactor.The online measurement of produced CO_2 was performed on 11 molecules (commercial names: Parachlorophenol,D-Glucose,Acid Blue 29,Atraton,Aspirin,Dimethoate,Aldicarb sulfone,Hydroquinone,(R)-Propranolol,Citric acid,Atrazine) to test the system efficiency.The experimental CO_2 value was compared with the theoretical TOC value calculated by means of the structure's formula.