Photo-Assisted Oxidation of Indigocarmine in an Acid Medium

Abstract

The kinetics of photo-oxidation of indigocarmine dye-5,5-indigosulfonate disodium (5,5-IDS)-in an acid medium has been studied to discover the effect of different parameters in the efficiency of the process. The experiments were conducted applying ultraviolet (UV)-polychromatic radiation to oxygen-saturated solutions. All kinetic experiments showed that the dye reaction order was zero, and its initial concentration did not influence the experimental rate constant. An increase in the rate was observed with an increasing UV radiation dose (D uv ) and/or the acidity. Temperatures-ranging from 290 K to 320 K-did not significantly affect the rate constant, indicating the photochemical activation of the oxidative process. 5-Isatinesulfonate sodium (5-IS) was identified as a photo-oxidation product. The effluent of the phototreatment had no color and contained no toxic products. Results showed that UV-induced oxidation of 5,5-IDS dye in an oxygensaturated aqueous medium, at room temperature, is an alternative treatment to conventional chemical oxidation for the decoloring of indigoid-dye wastewater from the textile industry.

Recent progress of metal–graphene nanostructures in photocatalysis

“…14,15 Nanomaterials have promising applications in dye degradation for wastewater treatment. [15][16][17][18][19] Currently, the most extensively studied nanomaterials for wastewater treatment include zero-valent metal nanoparticles (NPs)/NSs, metal oxides, and carbon-based NSs. 16,17,20,21 The above-mentioned dyes (Fig.…”

“…[15][16][17][18][19] Currently, the most extensively studied nanomaterials for wastewater treatment include zero-valent metal nanoparticles (NPs)/NSs, metal oxides, and carbon-based NSs. 16,17,20,21 The above-mentioned dyes (Fig. 1) are released directly into aqueous streams or as other waste forms from several industries, which causes environmental pollution through the direct discharge of carcinogenic and toxic substances into an aqueous medium.…”

“…1) are released directly into aqueous streams or as other waste forms from several industries, which causes environmental pollution through the direct discharge of carcinogenic and toxic substances into an aqueous medium. 16,17 The direct discharge of large quantities of toxic dyes is unavoidable because the individual textile industry consumes massive amounts of water and not all of the dyes can be combined totally with fibers during the dyeing procedure. 20,22 Globally, approximately 79 000 metric tons of dye materials are formed annually, with 10 to 50% of this amount being released directly into wastewater.…”

Recent Advances in Heterogeneous Photocatalytic Decolorization of Synthetic Dyes

“…The mentioned dyes are released in aqueous streams as effluents of several industries, including textiles, paper, leather, plastic, automobile, furniture, finishing sector, and others, which consequently create intense environmental pollution problems via the release of potential carcinogenic and toxic substances into the aqueous phase [ 22 , 23 ]. The discharge of an enormous volume of wastewater containing dyes is an inevitable consequence, because the textile industry consumes large quantities of water and all dyes cannot be completely combined with fibers during the dyeing process.…”

Modified Nondestructive Colorimetric Method To Evaluate the Variability of Oxygen Diffusion Rate through Wine Bottle Closures

“…We decided to investigate this phenomenon to understand its origin and its implications on the proposed method. Three possible causes of degradation were identified: oxygen, light, and heat − . Three trials were planned, combining the causes of degradation to simulate real storage conditions, and, for each trial, high oxygen entry (open bottles) and low oxygen entry (closed bottles) were compared.…”