Ultrasonic degradation of oxalic acid in aqueous solutions

Abstract

This paper describes the ultrasonic degradation of oxalic acid. The effects of ultrasonic power, H(2)O(2), NaCl, external gases on the degradation of oxalic acid were investigated. Reactor flask containing oxalic acid was immersed in the ultrasonic bath with water as the coupling fluid. Representative samples withdrawn were analysed by volumetric titration. Degradation degree of oxalic acid increased with increasing ultrasonic power. It was observed that H(2)O(2) has negative contribution on the degradation of oxalic acid and there was an optimum concentration of NaCl for enhancing the degradation degree of oxalic acid. Although bubbling nitrogen gave higher degradation than that for bubbling air, both gases (for 20 min before sonication and during sonication together) could not help to enhance the degradation of oxalic acid when compared with the degradation without gas passage.

Free radical generation induced by ultrasound in red wine and model wine: An EPR spin-trapping study

“…Except above-mentioned reasons, an increase of ultrasound power also contributes to an increase of acoustic amplitude. The collapsing time, temperature and pressure on the collapses of bubbles are all dependent on the acoustic amplitude, and the collapse of cavitation bubbles is more violent at higher acoustic amplitudes [26].…”

Review of Alternative Enhanced Chemical Cleaning Options for SRS Waste Tanks

“…These include; steam reforming, 65 wet air oxidation, 66 wet peroxide oxidation, 67 enzymatically catalyzed degradation, 68, 69 a pulse corona-discharge process, 70 ultrasonic assisted oxidations, 71 and sonophotocatalysis.…”

Photocatalytic Activity of the Iron-Containing Natural Composites in the Reaction of Oxidative Destruction of Oxalic Acid and Phenol

“…Currently, there are a number of techniques related to advanced oxidation processes (AOPs) that allow for the decomposition of soluble organic substances (SOS) to CO 2 and H 2 O [1]. These include ozonation [2,3], the effect of UV irradiation (UVI) [4], and the use of the Ruff-Fenton system (Fe 3+ + H 2 O 2 + UVI), during which there is a continuous photoreduction of salts Fe 3+ to Fe 2+ and the generation of •OH radicals [5].…”

“…These include ozonation [2,3], the effect of UV irradiation (UVI) [4], and the use of the Ruff-Fenton system (Fe 3+ + H 2 O 2 + UVI), during which there is a continuous photoreduction of salts Fe 3+ to Fe 2+ and the generation of •OH radicals [5]. In a homogeneous catalysis process, during the disproportionation of hydrogen peroxide by aqua ions, Fe 3+ free radicals •OH and HO 2 • are generated, which have high reactivity in oxidation reactions.…”