Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Sound cleans up water purification

16.05.2002


High-energy bubbles scour municipal water filters.

Sound waves could provide a greener way to make tap water taste better.

Ultrasound can make bubbles in water that could clean ceramic filters quickly and cheaply, say Linda Weavers and colleagues of Ohio State University, Columbus1. When the bubbles burst, they release energy that makes tiny, but fiercely powerful, jets of water that scour the filter’s surface and flush away debris.



Most municipal water treatment relies on slow, environmentally risky, chemical purification. A greener, more efficient alternative is to use membrane filters. These have pores so minuscule that they sieve out particles and microorganisms as small as viruses; but they get clogged easily. Fouled filters must be removed and either scrubbed or replaced, slowing the process and raising its cost.

Ultrasound cleaning could make membrane filtration the rule rather than the exception, hopes the Ohio team. "If you left the ultrasound running you could clean the filter while it is still in use, and keep it from ever getting clogged in the first place," says Weavers, who believes that, scaled up, the process could replace chemical water purification.

Philip Brandhuber of McGuire Environmental Consultants in Denver, Colorado, who specializes in membrane filtration of drinking water, agrees, saying he is pleased to see this "completely new approach to the fouling problem".

One potential problem is that the bursting bubbles could damage the filters. Ceramic filters are hard-wearing and heat resistant. But ultrasound cleaning could degrade the cheaper polymer membranes that are more widely used, points out Menachem Elimelech an environmental engineer at Yale University.

Others think that the benefits of a switch to ceramic filters would justify the costs. Tom Allsop, Water Department superintendent for Pinesdale, Montana - whose plants currently use sand and paper filters - says he’d jump at the chance to install an ultrasound-ceramic combination. "If it works as well as they claim, it would save us enormous amounts of money each year," says Allsop.

Brandhuber doubts that Allsop’s enthusiasm is representative of the drinking-water industry as a whole. The industry is inherently conservative, Brandhuber says, being concerned with public health and publicly funded. Before municipal plants are likely to invest, the technology must undergo much more rigorous investigation, he adds.

Weavers’ group intends to do just that. They are planning more tests to determine how well bubbles remove different contaminants and how different types of filter withstand the sound-induced scouring.


References
Chen, D., Weavers, L. K. & Walker, H. W. Using ultrasound to reduce ceramic membrane fouling by silica particles. Presented at the 2002 National Meeting of the American Chemical Society, Orlando, USA. (2002).

INGRID HOLMES | © Nature News Service

More articles from Ecology, The Environment and Conservation:

nachricht Upcycling 'fast fashion' to reduce waste and pollution
03.04.2017 | American Chemical Society

nachricht Litter is present throughout the world’s oceans: 1,220 species affected
27.03.2017 | Alfred-Wegener-Institut, Helmholtz-Zentrum für Polar- und Meeresforschung

All articles from Ecology, The Environment and Conservation >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Making lightweight construction suitable for series production

More and more automobile companies are focusing on body parts made of carbon fiber reinforced plastics (CFRP). However, manufacturing and repair costs must be further reduced in order to make CFRP more economical in use. Together with the Volkswagen AG and five other partners in the project HolQueSt 3D, the Laser Zentrum Hannover e.V. (LZH) has developed laser processes for the automatic trimming, drilling and repair of three-dimensional components.

Automated manufacturing processes are the basis for ultimately establishing the series production of CFRP components. In the project HolQueSt 3D, the LZH has...

Im Focus: Wonder material? Novel nanotube structure strengthens thin films for flexible electronics

Reflecting the structure of composites found in nature and the ancient world, researchers at the University of Illinois at Urbana-Champaign have synthesized thin carbon nanotube (CNT) textiles that exhibit both high electrical conductivity and a level of toughness that is about fifty times higher than copper films, currently used in electronics.

"The structural robustness of thin metal films has significant importance for the reliable operation of smart skin and flexible electronics including...

Im Focus: Deep inside Galaxy M87

The nearby, giant radio galaxy M87 hosts a supermassive black hole (BH) and is well-known for its bright jet dominating the spectrum over ten orders of magnitude in frequency. Due to its proximity, jet prominence, and the large black hole mass, M87 is the best laboratory for investigating the formation, acceleration, and collimation of relativistic jets. A research team led by Silke Britzen from the Max Planck Institute for Radio Astronomy in Bonn, Germany, has found strong indication for turbulent processes connecting the accretion disk and the jet of that galaxy providing insights into the longstanding problem of the origin of astrophysical jets.

Supermassive black holes form some of the most enigmatic phenomena in astrophysics. Their enormous energy output is supposed to be generated by the...

Im Focus: A Quantum Low Pass for Photons

Physicists in Garching observe novel quantum effect that limits the number of emitted photons.

The probability to find a certain number of photons inside a laser pulse usually corresponds to a classical distribution of independent events, the so-called...

Im Focus: Microprocessors based on a layer of just three atoms

Microprocessors based on atomically thin materials hold the promise of the evolution of traditional processors as well as new applications in the field of flexible electronics. Now, a TU Wien research team led by Thomas Müller has made a breakthrough in this field as part of an ongoing research project.

Two-dimensional materials, or 2D materials for short, are extremely versatile, although – or often more precisely because – they are made up of just one or a...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Fighting drug resistant tuberculosis – InfectoGnostics meets MYCO-NET² partners in Peru

28.04.2017 | Event News

Expert meeting “Health Business Connect” will connect international medical technology companies

20.04.2017 | Event News

Wenn der Computer das Gehirn austrickst

18.04.2017 | Event News

 
Latest News

Wireless power can drive tiny electronic devices in the GI tract

28.04.2017 | Medical Engineering

Ice cave in Transylvania yields window into region's past

28.04.2017 | Earth Sciences

Nose2Brain – Better Therapy for Multiple Sclerosis

28.04.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>