The 20 kHz sonochemical degradation of trace cyanide and dye stuffs in aqueous media

被引:41
作者
Hong, Q [1 ]
Hardcastle, JL [1 ]
McKeown, RAJ [1 ]
Marken, F [1 ]
Compton, RG [1 ]
机构
[1] Univ Oxford, Phys & Theoret Chem Lab, Oxford OX1 3QZ, England
关键词
D O I
10.1039/a903990b
中图分类号
O6 [化学];
学科分类号
0703 ;
摘要
Cyanide in alkaline aqueous solution is reported to be destroyed by a facile sonochemical process. In the presence of power ultrasound emitted from a horn probe with a frequency of 20 kHz and up to 60 W cm(-2) intensity a decay in the concentration with first order kinetics is monitored by ion selective electrode techniques. Characteristic features of the process are (i) a rate constant inversely proportional to the solution volume, (ii) a decrease in rate upon changing the gas phase in the reactor from air to argon, and (iii) an increase in rate in the presence of higher intensity ultrasound. With these characteristic features the process is interpreted in terms of a sonochemical degradation initiated by a high energy intermediate such as OH. produced in violent cavitation events. Further evidence for this mechanistic conclusion comes from complementary experiments employing low concentrations of dyes (alizarin and Procion Blue) in aqueous solutions. The sonochemical degradation of these dye solutions with 20 kHz power ultrasound is monitored by following the UV-VIS absorption. Characteristic features for the dye degradation process are in agreement with those observed for the cyanide sonolysis and therefore attributed to the same kind of sonochemical mechanism. The sonochemical degradation of cyanide proceeds with a rate an order of magnitude faster than that of the dye bleaching, possibly due in part to the faster rate of diffusion of cyanide compared to the larger organic dye molecules.
引用
收藏
页码:845 / 849
页数:5
相关论文
共 42 条
[1]   Sonochemistry .2. Effects of ultrasounds on homogeneous chemical reactions and in environmental detoxification [J].
Colarusso, P ;
Serpone, N .
RESEARCH ON CHEMICAL INTERMEDIATES, 1996, 22 (01) :61-89
[2]   Sonochemical degradation rates of volatile solutes [J].
Colussi, AJ ;
Hung, HM ;
Hoffmann, MR .
JOURNAL OF PHYSICAL CHEMISTRY A, 1999, 103 (15) :2696-2699
[3]   Sonoelectrochemical processes: A review [J].
Compton, RG ;
Eklund, JC ;
Marken, F .
ELECTROANALYSIS, 1997, 9 (07) :509-522
[4]   THE REDUCTION OF FLUORESCEIN IN AQUEOUS-SOLUTION (AT PH-6) - A NEW DISP2 REACTION [J].
COMPTON, RG ;
MASON, D ;
UNWIN, PR .
JOURNAL OF THE CHEMICAL SOCIETY-FARADAY TRANSACTIONS I, 1988, 84 :483-489
[5]   Sonovoltammetric measurement of the rates of electrode processes with fast coupled homogeneous kinetics: Making macroelectrodes behave like microelectrodes [J].
Compton, RG ;
Marken, F ;
Rebbitt, TO .
CHEMICAL COMMUNICATIONS, 1996, (09) :1017-1018
[6]   Sonoelectrochemical production of hydrogen peroxide at polished boron-doped diamond electrodes [J].
Compton, RG ;
Marken, F ;
Goeting, CH ;
McKeown, RAJ ;
Foord, JS ;
Scarsbrook, G ;
Sussmann, RS ;
Whitehead, AJ .
CHEMICAL COMMUNICATIONS, 1998, (18) :1961-1962
[7]   Pulsed sonochemistry [J].
Dekerckheer, C ;
Bartik, K ;
Lecomte, JP ;
Reisse, J .
JOURNAL OF PHYSICAL CHEMISTRY A, 1998, 102 (46) :9177-9182
[8]   HETEROGENEOUS PHOTOCATALYTIC OXIDATION OF CYANIDE AND SULFITE IN AQUEOUS-SOLUTIONS AT SEMICONDUCTOR POWDERS [J].
FRANK, SN ;
BARD, AJ .
JOURNAL OF PHYSICAL CHEMISTRY, 1977, 81 (15) :1484-1488
[9]   CHEMICAL EFFECTS OF CONTINUOUS AND PULSED ULTRASOUND IN AQUEOUS-SOLUTIONS [J].
HENGLEIN, A .
ULTRASONICS SONOCHEMISTRY, 1995, 2 (02) :S115-S121
[10]  
Henglein A., 1993, ADV SONOCHEMISTRY, P17