Microwave-assisted rapid decomposition of persulfate

Microwave irradiation has been a promising alternative to conduct several chemical reactions. In this work the microwave effects in potassium persulfate decomposition rate, under controlled conditions of temperature and microwave power, were evaluated. Higher decomposition rate constants were obtained in microwave irradiated reactions in comparison with conventional heated ones. To study the effect of high power microwave irradiation, a pulsed irradiation strategy was developed, in which the samples were repeatedly heated within short intervals of time at high power levels (500 or 1400 W). A great decomposition percentage was achieved in shorter irradiation times, showing the kinetic advantages of microwave-assisted reactions. However, it was found no differences in the reaction yields, even when high power levels were involved, proving that microwave enhancements may arise only from the ability to quickly provide a large amount of energy to the reaction medium. (C) 2009 Elsevier Ltd. All rights reserved.