Skip to main content

“SONICATION-ASSISTED AIR FLOTATION”

Buy Article:

$9.50 plus tax (Refund Policy)

Or sign up for a free trial

Oil and grease are common industrial contaminants. Several techniques are currently used to treat oily wastewaters, including (1) oil/water separators, (2) dissolved air flotation, and (3) supercritical extraction. Oil/water separators rely upon gravity separation to separate oily materials (density) from water. This allows floating matter to rise and remain on the surface until it can be skimmed off or removed, while the liquid flows continuously through deep outlets or under partitions, curtain walls, or deep scum boards. Materials collected on the surface of skimming tanks include oil, grease, pieces of cork and wood, and vegetable debris and fruit skins in households and in industry. Dissolved air flotation relies upon interfacial phenomena to attract/coalesce oily materials from water. Use of surfactants facilitates the removal of oily components from solution. This technique accommodates high surface-loading rates, and can achieve high removals of grease and floatable material. Supercritical extraction involves fluid extraction performed at supercritical thermodynamic conditions. This is an attractive alternative to solvent extraction, due to better mass transfer properties of supercritical fluids, shorter extraction times, and ease of extract separation.

Sonication involves transmittal of sound waves through a fluid in a series of alternating cavitation cycles. Compression cycles exert a positive pressure on the liquid, pushing molecules together, while expansion cycles exert a negative pressure, pulling molecules away from each other. In addition to microscale effects (cavitation), it is known that sonication also effects macroscopic mixing. During cavitation, the liquid structure is disrupted, forming tiny microbubbles. These microbubbles grow to a critical size through a process known as rectified diffusion and finally implode, releasing a large amount of energy. Temperatures on the order of 5,000°K and pressures up to 500 to 1000 atmospheres have been observed in microbubble implosions, while the bulk solution stays near ambient conditions.

Preliminary results indicate that the combination of sonication and air flotation may result in improved removal of oily materials from industrial wastewaters. The results indicate that the removal of benzene, toluene, and ethylbenzene is enhanced through the combination of sonication and air flotation over the case of mixing alone, sonication alone, and air flotation alone.
No Reference information available - sign in for access.
No Citation information available - sign in for access.
No Supplementary Data.
No Article Media
No Metrics

Document Type: Research Article

Publication date: 2002-01-01

More about this publication?
  • Proceedings of the Water Environment Federation is an archive of papers published in the proceedings of the annual Water Environment Federation® Technical Exhibition and Conference (WEFTEC® ) and specialty conferences held since the year 2000. These proceedings are not peer reviewed.

    A subscription to the Proceedings of the Water Environment Federation includes access to most papers presented at the annual WEF Technical Exhibition and Conference (WEFTEC) and other conferences held since 2000. Subscription access begins 12 months after the event and is valid for 12 months from month of purchase. A subscription to the Proceedings of the Water Environment Federation is included in Water Environment Federation (WEF) membership.

    WEF Members: Sign in (right panel) with your IngentaConnect user name and password to receive complimentary access. Access begins 12 months after the conference or event
  • Subscribe to this Title
  • Membership Information
  • About WEF Proceedings
  • WEFTEC Conference Information
  • Learn about the many other WEF member benefits and join today
  • Ingenta Connect is not responsible for the content or availability of external websites
  • Access Key
  • Free content
  • Partial Free content
  • New content
  • Open access content
  • Partial Open access content
  • Subscribed content
  • Partial Subscribed content
  • Free trial content
Cookie Policy
X
Cookie Policy
Ingenta Connect website makes use of cookies so as to keep track of data that you have filled in. I am Happy with this Find out more