BUNSEKI KAGAKU Vol. 55, No. 8, pp. 567 _ 5712006 567 2006 The Japan Society for Analytical Chemistry R 1 2 2 OH Cu Fe Zn 100 khz45 khz28 khz 1 1)2) 3) OH PCB 4)9) VOC VOC 10)11) 1 : 599 8531 1 1 2 :8528521 1 14 OH VOC 12)13) Klabunde 12)
568 BUNSEKI KAGAKU Vol. 55 2006 2 GS-200 A Zn Cu 1 Fe 100 mesh Ar 99.99 2 Kaijo TA-4021 : 200 khz : 200 W 1.6 W/cm 2 14) Honda 3 W-113 : 2845 100 khz : 100 W 202 2l 28 khz 37 W45 khz 38 W 100 khz 31 W 1mm 14) 65 ml Ar 30 Ar 1000 ppm 1 Ar AA 100 I 3 λ max351 nmε 26000 M 1 cm 1 Shimadzu UV-2100 Horiba F-22 Ar Fricke 7) Fricke 0.4 M H 2SO 450 mm FeSO 4 Fe 2 Fe 3 λ max 304 nmε 2174 M 1 cm 1 3 31 OH 1 15) H 2O HOH 1 HOH H 2O 2 2H H 2 3 2OH H 2O 2 4 Fricke 9.5 µm/min 4 OH 19 µm/min Fe 2 5 Weissler 16)
: 569 Fig. 1 Decomposition of CCl 4 by ultrasonic irradiation in the absence and presence of metal powders Condition : CCl 4 1000 ppm, metal powder 0.1 g, Ar atmosphere, 10 min irradiation by ultrasound cleaning bath with 28 khz CCl 4H 2O CO2HClCl 2 5 760 µm/min OH Nagata 10)11) 28 khz 12 µm/min H-OH 497 kj mol 1 Cl-CCl 3 288 kj mol 1 17) Cl-C H-O 32 VOC Fig. 1 CuFeZn Fig. 1 18) Cu Fe Zn Zn 33 Zn Klabunde 6 7 12)19) 2Zn(s)2CCl 42H 2O ZnCl 2(aq)Zn(OH) 2(s)2CHCl 3 6 4Zn(s)CCl 44H 2O 2ZnCl 2(aq)2Zn(OH) 2(s)CH 4 7 Zn 6 7 Zn Cu 2 2e Cu ; 0.337VFe 2 2e Fe ; -0.440VZn 2 2e Zn ; -0.7628V Zn 1 Klabunde Zn 12) Zn Zn Fig. 2 28 khz 2845100 khz 935826 µm 14)20)
570 BUNSEKI KAGAKU Vol. 55 2006 Fig. 2 Effect of ultrasound frequency on the decomposition of CCl 4 in the presence of zinc powder Condition : CCl 4 1000 ppm, zinc powder 0.1 g, Ar atmosphere, 10 min irradiation by ultrasound cleaning bath Fig. 3 Decomposition of volatile chlorinated hydrocarbons (VOC) by ultrasound cleaning bath in the absence and presence of zinc powder : CCl 4 Zn, : CCl 2CCl 2 Zn, : CCl 2CHCl Zn, : CCl 4, : CCl 2CCl 2, : CCl 2CHCl ; Condition : VOC 1000 ppm, zinc powder 0.1 g, Ar atmosphere 14) Fig. 3 Zn Zn OH Zn Zn Zn Suslick Zn Zn 21) Hoffmann Fe 22)23) B 21 COE 1) I. Rezic, A. J. M. Horvat, S. Babic, M. Kastelan- Macan : Ultrasonics Sonochem., 12, 477 2) A. C. Kimbaris, N. G. Siatis, D. J. Daferera, P. A. Tarantilis, C. S. Pappas, M. G. Polissiou : Ultrasonics Sonochem., 13, 54 (2006). 3) K. A. Borthwick, T. E. Love, M. B. McDonnell, W. T. Coakley : Anal. Chem., 77, 7242 4),, :, 40, 13 (2003). 5) Y. Nagata, K. Hirai, K. Okitsu, T. Dohmaru, Y. Maeda : Chem. Lett., 1995, 203. 6) H. Moriwaki, Y. Takagi, M. Tanaka, K. Tsuruho, K. Okitsu, Y. Maeda : Environ. Sci. Tech., 39, 3388 7) K. Okitsu, K. Iwasaki, Y. Yobiko, H. Bandow, R. Nishimura, Y. Maeda : Ultrasonics Sonochem., 12, 255
: 571 8) H. Okuno, B. Yim, Y. Mizukoshi, Y. Nagata, Y. Maeda : Ultrasonics Sonochem., 7, 261 (2000). 9) Y. G. Adewuyi : Environ. Sci. Technol., 39, 3409 10) K. Inazu, Y. Nagata, Y. Maeda : Chem. Lett., 1993, 57. 11) Y. Nagata, Y. Kurosaki, M. Nakagawa, Y. Maeda : Chem. Express, 8, 657 (1993). 12) T. N. Boronina, K. J. Klabunde, G. B. Sergeev : Environ. Sci. Technol., 29, 1511 (1995). 13) L. J. Matheson, P. G. Tratnyek : Environ. Sci. Technol., 28, 2045 (1994). 14) K. Okitsu, A. Yue, S. Tanabe, H. Matsumoto, Y. Yobiko, Y. Yoo : Bull. Chem. Soc. Jpn., 75, 2289 (2002). 15) K. Makino, M. M. Mossoba, P. Riesz : J. Phys. Chem., 87, 1369 (1983). 16) A. Weissler, H. W. Cooper, S. Snyder : J. Am. Chem. Soc., 72, 1769 (1950). 17) D. R. Lide (Ed.): CRC Handbook of Chemistry and Physics 83 rd edition, 9-75, (2002-2003), (CRC Press, London). 18),,, : 9, p. 56 (2000). 19) T. N. Boronina, I. Lagadic, G. B. Sergeev, K. J. Klabunde : Environ. Sci. Technol., 32, 2614 (1998). 20) E. A. Neppiras : Phys. Rep., 61, 159 (1980). 21) K. S. Suslick, S. J. Doktycz : J. Am. Chem. Soc., 111, 2342 (1989). 22) H-M. Hung, M. R. Hoffmann : Environ. Sci. Technol., 32, 3011 (1998). 23) H-M Hung, F. H. Ling, M. R. Hoffmann : Environ. Sci. Technol., 34, 1758 (2000). Effect of Transition Metal Powder and Low-Energy Ultrasound Frequency on Degradation Rate of Chlorinated Hydrocarbons in Water Kenji OKITSU 1, Yuichiro YOSHIOKA 2 and Shuji TANABE 2 1 Graduate School of Engineering, Osaka Prefecture University, 1 1, Gakuen-cho, Sakai-shi, Osaka 599 8531 2 Faculty of Engineering, Nagasaki University, 1 14, Bunkyo-machi, Nagasaki-shi, Nagasaki 852 8521 (Received 22 February 2006, Accepted 12 May 2006) The degradation of volatile chlorinated hydrocarbons such as tetrachloroethylene, trichloroethylene and tetrachloromethane, was investigated in aqueous solution using a low-energy ultrasound cleaning bath. In this experiment, no formation of the OH radical was observed, suggesting that no generation of a high temperature cavitation bubble to pyrolyze the water molecule. On the other hand, it was observed that the degradation of tetrachloromethane slowly proceeded during irradiation. To enhance the rate of degradation, we investigated the effect of transition metal powders and frequency of ultrasound. The rate of degradation increased extremely upon the addition of metal powders and was in the order of nonecufezn. The frequency of the ultrasound also affected the rate of degradation ; the order was 100 khz 45 khz28 khz. These phenomena suggested that a shock wave formed from acoustic cavitation removed an inactive oxide surface of metal powders, resulting in an effective enhancement of the reductive dechlorination reactions. Keywords : volatile chlorinated hydrocarbons ; reductive dechlorination ; activation of transition metals ; effect of ultrasound frequency, shock wave.