Abstract
Herein, we report the effect of sonoluminescence and an initial dye concentration on the sonophotocatalysis of TiO2 for the degradation of eosin B, a textile dye. We first investigated the light illuminated during ultrasound irradiation (sonoluminescence) by photographic images, a radical indicator (luminol), and photoluminescence spectra of the detection range of 300–1050 nm. Next, we examined the synergistic effect of sonolysis on photocatalysis by comparing the dye degradation of sonophotocatalysis to that of individual contributions of sonolysis and photocatalysis. Since it was found that the synergist effect is highly engaged with a dye concentration and sonication power, we conducted the comparison test in different concentrations of eosin B (5 and 20 mg/L) and ultrasound powers (35.4, 106.1, and 176.8 W/cm2). When the concentration of dyes was low, negative synergistic effects were found at all ultrasound powers, whereas at the high concentration, positive synergistic effects were observed at high ultrasound power. This difference in synergistic effects was explained by the influence of ultrasound on dynamics of dye adsorption on the TiO2 surface.
Highlights
IntroductionWastewater treatment has become very important. Especially, increasing amounts of organic substances dissolved in water, such as dyes, chlorinated organics, and antibiotics, have emerged as a serious problem and the need for development of advanced oxidation processes (AOPs) has dramatically increased
With industrial development, wastewater treatment has become very important
The mechanism of most advanced oxidation processes (AOPs) involves the formation of OH· radicals, a powerful oxidant with its oxidation potential of 2.8 eV, but ways of its generation vary by different AOPs, from sonolysis of water to activation of oxidants, such as H2 O2 and ozone [5,6]
Summary
Wastewater treatment has become very important. Especially, increasing amounts of organic substances dissolved in water, such as dyes, chlorinated organics, and antibiotics, have emerged as a serious problem and the need for development of advanced oxidation processes (AOPs) has dramatically increased. Among several AOPs, oxidative catalytic reactions such as the Fenton process (a Fe2+ -mediated catalytic reaction of H2 O2 conversion to a hydroxyl radical (OH·)) and photocatalysis, ozone-based oxidations, H2 O2 -based oxidations, UV-based. The mechanism of most AOPs involves the formation of OH· radicals, a powerful oxidant with its oxidation potential of 2.8 eV, but ways of its generation vary by different AOPs, from sonolysis of water to activation of oxidants, such as H2 O2 and ozone [5,6]. Sonolysis undergoes by OH· radicals, which are generated by ultrasonic irradiation of water. During the ultrasonic irradiation of water, micro-bubbles form, oscillate, grow and collapse (generally called as acoustic cavitation), by which a locally concentrated energy strong enough to dissociate water vapor to OH· radicals and hydrogen atoms arises [7]. Sonolysis can be used to break down hard substances, and decompose large organic molecules into small fragments [8,9]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
