Ultrasonic cavitation induced degradation of Congo red in aqueous solutions

Abstract

Ultrasonic cavitation induced degradation of Congo red in aqueous solution was investigated for a variety of operating conditions. It is found that the degradation of Congo red in aqueous solution follows pseudo-first-order reaction kinetics and the degradation rate is dependent on the initial concentration of Congo red, the temperature and pH of the aqueous medium. The effects of Fe 2+ and Fenton reagent addition on the sonochemical degradation of Congo red were also investigated. The results obtained here indicate that the degradation rate of Congo red in aqueous solution was substantially accelerated by Fe 2+ , NaCl or Fenton reagent addition.

Evaluation of Ultrasonic Oxidation of Diethyl Phthalate Using Box-Behnken Design with Response Surface Methodology

“…Seymour et al (1997) investigated that the ultrasonic oxidation enhancements were observed 6-fold for chlorobenzene, 7-fold for p-ethylphenol, . Meshram et al (2010) also obtained the similar result that the sonolysis reaction rate constants of Congo red were 1.14×10 , respectively. But it is easy to see that all these studies were carried out under very high concentration of NaCl compared with that of in this study.…”

La Loaded TiO2Encapsulated Zeolite Y Catalysts: Investigating the Characterization and Decolorization Process of Amaranth Dye

“…This low activity of the ultrasonic was ascribed to the insufficient amount of • OH radicals generated by ultrasonic alone since radicals in this case were generated only through the dissociation of water molecules. As a result, the oxidation of the hydrophilic dye molecules could be only effective when these radicals were transferred from the interface of the cavitation bubbles into the bulk solution [29]. However, encapsulation of titanium nanoparticles into the pores of zeolite gave significant enhancement in the sonocatalytic activity with maximum degradation efficiency of 50%.…”

Effect of Calcination Temperature on Structural Properties and Photocatalytic Activity of Ceria Nanoparticles Synthesized Employing Chitosan as Template

“…CR is toxic to organisms and it is a suspected carcinogen and mutagen. Synthetic dyes, such as CR, are difficult to biodegrade due to their complex aromatic structures, which provide them physicochemical, thermal, and optical stability [20,21]. Physicochemical or chemical treatment of such wastewaters is, however, possible: color removal by ultrafiltration [22], ozonation [23], coagulation [24], adsorption process [18], and so forth.…”

“…Therefore, it is important to find alternatives to the degradation of reactive azo dyes in an aqueous solution and destruction of several classes of organic dyes. Most conventional treatment processes are effective in water treatment, but they only transfer the contaminants from one medium to another or generate waste that requires further treatment and disposal [19][20][21]. In this sense, photocatalytic reactions on irradiated semiconductor powders have a good potential for the removal of organic and inorganic waste materials from water [27].…”