Optimized photocatalytic degradation of Reactive Blue 2 by TiO₂/UV process

Abstract

The photocatalytic degradation of synthetic dye solution of Reactive Blue 2 was investigated using UV irradiation in aqueous suspension of nanotitania as photocatalyst and H2O2 as electron acceptor in a slurry photoreactor. To determine the optimum condition of decolorization, the influential parameters including initial dye concentration, catalyst quantity, hydrogen peroxide concentration, pH value and UV light intensity were evaluated using the Taguchi statistical method. The results indicated that compared to the other parameters, UV light intensity was the most effective. The theoretically predicted value of decolorization efficiency (95.48%) was confirmed by the experimental value (95.22%). The mineralization was considered significant with regard to the obtained values of total organic carbon (TOC) analysis (92.52%) and chemical oxygen demand (COD) analysis (94.05%) in the optimum condition. Investigations were also carried out to determine the appropriate adsorption isotherm and kinetic model in the optimum condition. The obtained optimum condition for dye removal was finally examined applying a real sample of textile wastewater containing the dye.

Self-assembly modified-mushroom nanocomposite for rapid removal of hexavalent chromium from aqueous solution with bubbling fluidized bed

“…In Table 3 , the maximum value of among all four factors in three levels was bolded. These maximum values indicated the optimization conditions for Cr (VI) removal process 13 14 19 . The optimum conditions are as follows: the dosage of adsorbent is 5 g; duration of treatment is 2 hours; the concentration of modifier is 1% (v/v) and the diameter of adsorbent is between 0.3 mm and 0.45 mm.…”

Recent Advances in Heterogeneous Photocatalytic Decolorization of Synthetic Dyes

“…The Environmental Protection Agency (EPA) has approved the inclusion of AOP as the best available technology to meet the standard with specifications that provide safe and sufficient pollution control of industrial processes and remediation of contaminated sites [ 42 , 63 ].…”

“…TiO 2 was found to be the most efficient photocatalyst for photodegradation of sulfur dyes because of faster electron transfer of molecular oxygen [ 264 – 266 ]. Furthermore, TiO 2 photocatalyst is largely available as a nontoxic, inexpensive, and with relatively high chemical stability [ 42 ]. It has been noted that the photocatalytic degradation of sulfur dyes in solution is initiated by photoexcitation of the semiconductor, followed by formation of an electron-hole pair on the semiconductor surface [ 267 ].…”

“…Only 45 to 47% of dyes have been reported as organic dyes with biodegradable and solubility characteristics. The remaining 55 to 53% of dyes are toxic and their persistence in wastewater has recently become an issue of interest [ 8 , 41 , 42 ]. Synthetic or poisoning dyes engaged more often on industrial scale are acid dyes, water soluble anionic, basic dyes-water soluble cationic, substantive dyes-alkaline, vat dyes-water soluble alkali metal salt, azoic dyes, sulfur dyes, and chrome dyes.…”

Copper and Nitrogen Co-Doping Effect on Visible-Light Responsive Photocatalysis of Plasma-Nitrided Copper-Doped Titanium Oxide Film

“…Titanium dioxide (TiO 2 ) is well known as chemically stable and harmless material, and has been applied widely in various fields such as photocatalysts [1] [2] [3], dye-sensitized solar cells [4] [5] [6], water splitting [3] [7], and so on. In recent years, it has been received a great deal of attention especially as an environmental purification materials, because of its photocatalytic decomposition of persistent organic pollutants, and photo-induced hydrophilicity [8] [9] [10] [11].…”