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 Clean air for a sustainable future in Manila
22.08.2019 | Leibniz-Institut für Troposphärenforschung e. V.

nachricht A Rescue Plan for the Ocean
16.08.2019 | Institute for Advanced Sustainability Studies e.V.

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: Physicists create world's smallest engine

Theoretical physicists at Trinity College Dublin are among an international collaboration that has built the world's smallest engine - which, as a single calcium ion, is approximately ten billion times smaller than a car engine.

Work performed by Professor John Goold's QuSys group in Trinity's School of Physics describes the science behind this tiny motor.

Im Focus: Quantum computers to become portable

Together with the University of Innsbruck, the ETH Zurich and Interactive Fully Electrical Vehicles SRL, Infineon Austria is researching specific questions on the commercial use of quantum computers. With new innovations in design and manufacturing, the partners from universities and industry want to develop affordable components for quantum computers.

Ion traps have proven to be a very successful technology for the control and manipulation of quantum particles. Today, they form the heart of the first...

Im Focus: Towards an 'orrery' for quantum gauge theory

Experimental progress towards engineering quantized gauge fields coupled to ultracold matter promises a versatile platform to tackle problems ranging from condensed-matter to high-energy physics

The interaction between fields and matter is a recurring theme throughout physics. Classical cases such as the trajectories of one celestial body moving in the...

Im Focus: A miniature stretchable pump for the next generation of soft robots

Soft robots have a distinct advantage over their rigid forebears: they can adapt to complex environments, handle fragile objects and interact safely with humans. Made from silicone, rubber or other stretchable polymers, they are ideal for use in rehabilitation exoskeletons and robotic clothing. Soft bio-inspired robots could one day be deployed to explore remote or dangerous environments.

Most soft robots are actuated by rigid, noisy pumps that push fluids into the machines' moving parts. Because they are connected to these bulky pumps by tubes,...

Im Focus: Vehicle Emissions: New sensor technology to improve air quality in cities

Researchers at TU Graz are working together with European partners on new possibilities of measuring vehicle emissions.

Today, air pollution is one of the biggest challenges facing European cities. As part of the Horizon 2020 research project CARES (City Air Remote Emission...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

The power of thought – the key to success: CYBATHLON BCI Series 2019

16.08.2019 | Event News

4th Hybrid Materials and Structures 2020 28 - 29 April 2020, Karlsruhe, Germany

14.08.2019 | Event News

What will the digital city of the future look like? City Science Summit on 1st and 2nd October 2019 in Hamburg

12.08.2019 | Event News

 
Latest News

Nano-thermometer takes temperature inside cells

23.08.2019 | Life Sciences

OHIO professor Hla develops robust molecular propeller for unidirectional rotations

22.08.2019 | Life Sciences

127-year-old physics problem solved

22.08.2019 | Physics and Astronomy

VideoLinks
Science & Research
Overview of more VideoLinks >>>