Abstract
![CDATA[The propagation of high power sound waves through a liquid can initiate the phenomenon of cavitation, the bubbles arising from the dissolution of air or vaporisation of the liquid during the rarefaction phase of the wave. Bubble collapse produces highly localised temperatures and pressures of some 5000 K and 1000 atmospheres respectively. Solid particles in a slurry act as foci for the nucleation of bubbles, the collapse of which generates a high velocity jet directed towards the solid surface. The extreme conditions generated by the non-linear shock wave resulting from bubble collapse are then localised on the surface of the solid. Most POPs (persistent organic pollutants) are hydrophobic and are readily adsorbed on the surface of solid particles, so that the cavitation energy generated by high power ultrasound in a slurry of such material is selectively directed towards the contaminants. Because the extreme conditions are localised on the surface of the particles, the bulk solution temperature remains quite low and the decomposition products are immediately quenched, avoiding recombination reactions. We have exploited this process to achieve very high destruction rates for several of the most notorious contaminants at energy costs far below those of competing technologies. The technique, which is at pilot plant stage, shows great promise with the advantages of in-situ treatment and reduced operating and capital costs compared with conventional technologies.]]
Original language | English |
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Title of host publication | 16th National Congress of the Australian Institute of Physics: Physics for the Nation: Manning Clark Centre, Australian National University of Canberra, Sunday 30 January to Friday 4 February 2005: Congress Handbook and Abstracts |
Publisher | Australian National University |
Number of pages | 1 |
ISBN (Print) | 0959806482 |
Publication status | Published - 2005 |
Event | Australian Institute of Physics. National Congress - Duration: 30 Nov 2008 → … |
Conference
Conference | Australian Institute of Physics. National Congress |
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Period | 30/11/08 → … |
Keywords
- sound-waves
- soil pollution
- cavitation
- pollutants