CINETIC STUDY OF PHOTOCATALYTIC DEGRADATION BY THE (TiO2/UV) SYSTEM OF INDIGO CARMINE DYE IN AQUEOUS SOLUTION

The persistence of synthetic dyes in the environment and the ineffectiveness of most conventional depollution techniques have led the scientific community to turn to advanced oxidation processes for eliminating these dyes from water. The aim of this work was to experiment with heterogeneous photocatalysis in the degradation of indigo dye in aqueous solution. The catalyst used was titanium dioxide in the anatase PC 500 form, irradiated by a polychromatic ultraviolet lamp with a wavelength λ= 365 nm. This technique proved effective, with a 77% degradation rate compared with photolysis, which removed only 17% of the indigo dye under the same conditions. Also, this work showed that low-concentration solutions were easily degraded with total decolourisation of the 12 mg/L molecule after 4 hours compared with 80% elimination of the 32 mg/L solution.The study of the influence of light intensity showed an increase in the rate of degradation of the molecule when the number of lamps placed in the reactor was increased. Total degradation was observed when 4 lamps were used for 120 minutes of irradiation.