Quantification of Radicals Generated in a Sonicator

Document Type : Research Paper

Authors

1 Environmental and Nano Science Research, Chemistry Department, University of The Western Cape, Cape Town, South Africa

2 Chemistry Department Cape Peninsula University of Technology

Abstract

The hydroxyl radical (OH•) is a powerful oxidant produced as a consequence of cavitation in water. It can react nonspecifically in breaking down persistent organic pollutants in water into their mineral form. It can also recombine to form hydrogen peroxide which is very useful in water treatment. In this study, terephthalic acid (TA) and potassium iodide dosimetry were used to quantify and investigate the behaviour of the generated OH radical in a laboratory scale sonicator. The 2-hydroxyl terephthalic acid (HTA) formed during terephthalic acid dosimetry was determined by optical fibre spectrometer. The production rate of HTA served as a means of evaluating and characterizing the OH• generated over given time in a sonicator. The influence of sonicator power intensity, solution pH and irradiation time upon OH• generation were investigated. Approximately 2.2 ´ 10-9 M s-1 of OH radical was generated during the sonication process. The rate of generation of the OH radicals was established to be independent of the concentration of the initial reactant. Thus, the rate of generation of OH• can be predicted by zero order kinetics in a sonicator.

Keywords


1         S. Liang, L. S. Palencia, R. S. Yatee, M. K. Davis, J.-M. Bruno and R. L. WolfeE, J. Am. Water Works Assoc., 91, 104–114.
2         K. M. Kalumuck and G. L. Chahine, in PhD Proposal, 1998, vol. 1, p. 10.
3         J. Rae, M. Ashokkumar, O. Eulaerts, C. Von Sonntag, J. Reisse and F. Grieser, 2005, 12, 325–329.
4         D. H. Bremner, A. E. Burgess and R. Chand, Curr. Org. Chem., 2011, 15, 168–177.
5         T. Y. Wu, N. Guo, C. Y. Teh and J. X. W. Hay, Adv. Ultrasound Technol. Environ. Remediat., 2013, 5–12.
6         W. He, Y. Liu, W. G. Wamer and J.-J. Yin, J. food drug Anal., 2014, 22, 49–63.
7         A. Mašláni and V. Sember, J. Spectrosc., 2014, 2014, 6.
8         L. P. Amin, P. R. Gogate, A. E. Burgess and D. H. Bremner, Chem. Eng. J., 2010, 156, 165–169.
9         N. Tinne, B. Kaune, A. Kruger and T. Ripken, PLoS One, 2014, 9, 1–26.
10       M. Sahni and B. R. Locke, Ind. Eng. Chem. Res., 2006, 5819–5825.
11       A. Sazgarnia and A. Shanei, Int. J. Photoenergy, 2012, 2012, 1–5.
12       Y. Manevich, K. D. Held and J. E. Biaglow, Radiat. Res., 1997, 148, 580–591.
13       G. P. Bronislaw K. Glód, Chem. Anal. (Warsaw), 2002, 399, 399–407.
14       A. Sazgarnia and A. Shanei, 2012, 2012.
15       C. A. Wakeford, R. Blackburn and P. D. Lickiss, Ultrason. Sonochem., 1999, 6, 141–148.
16       A. . E. Velikova, V., I . Yordanov, Plant Sience, 2000, 151, 59–66.
17       L. Villeneuve, L. Alberti, J. Steghens, J. Lancelin and J. Mestas, Ultrason. - Sonochemistry, 2009, 16, 339–344.
18       I. Hua and M. R. Hoffmann, Environ. Sci. Technol, 1997, 31, 2237–2243.
19       J. González-garcía, V. Sáez, I. Tudela, M. I. Díez-garcia, M. D. Esclapez and O. Louisnard, 2010, 28–74.
20       E. Ginsburg, M. D. Kinsley and  a Quitral, Adm. Radiol. J., 1998, 17, 17–20.
21       A. H. Barati, M. Mokhtari-dizaji, H. Mozdarani and Z. Bathaie, Ultrason. Sonochem., 2007, 14, 783–789.
22       J. S. Taurozzi, V. a Hackley and M. R. Wiesner, NIST Spec. Publ. 1200-2, 2012.
23       M. Mehrvar, W. A. Anderson and M. Moo-young, Int. J. Photoenergy, 2001, 3, 187–191.
24       H. M. S. Z. B. Z. M. H. Barati Amir H M. Mokhtari -Dizaji, Iran. J. Radiat. Res., 2006, 3 (4), 163–169.
25       L. Stricker, Laura Stricker, Physics of Fluids, University of Twente, P.O. Box 217, 7500 AE Enschede, The Netherlands http://pof.tnw.utwente.nl, 2013.