NUS Researchers Develop Highly Efficient Nature-Inspired Membrane that Can Lower Water Purification Cost

PR62810

SINGAPORE, Dec. 10, 2015 /PRNewswire=KYODO JBN/ --

The growing demand for potable water calls for low energy and cost effective

methods for water purification. Inspired by the natural water purification

systems of the roots of the mangrove plant and the human kidney, a team of

researchers from the National University of Singapore (NUS) Environmental

Research Institute (NERI) has engineered a novel biomimetic membrane that can

purify water at low pressure, thus reducing energy costs. This new technology

can potentially reduce water purification costs by up to 30 per cent.

The water purification industry today faces a major challenge of high energy

costs incurred by current membrane systems to recover water from saline

sources. Industrial water purification processes are costly because they

require high hydraulic or osmotic pressures to push water molecules to filter

through the membrane systems.

Led by Associate Professor Tong Yen Wah who is also from the Department of

Chemical and Biomolecular Engineering at NUS, the team has designed and

fabricated a new aquaporin-incorporated water purification and treatment system

that is highly efficient. Aquaporins are membrane proteins that selectively

conduct water molecules in and out of cells, preventing the passage of ions and

other solutes.

Also known as the water channels in living cell membranes, aquaporins have been

found to be the functional unit of nature's water purification systems. These

channels provide nature's examples of membrane structures that allow high

volume of water molecules to pass through a small surface area at very low

pressures, leaving impurities like salt behind.

With the presence of aquaporin, mangrove plants which have adapted to survive

in salt water, are able to filter between 90 and 95 per cent of the salt at

their roots, while the human kidney is able to purify up to 150 litres of water

daily.

The team is among the first in the world to have succeeded in placing aquaporin

proteins onto polymer membranes to act as channels that allow only water to go

through very quickly, at low pressures and low energy.

Explained Assoc Prof Tong, "The biomimetic membrane is constructed to mimic the

layers of cells on the roots of mangrove trees by embedding nano-sized

aquaporin-vesicles onto a stable and functional ultrafiltration substrate

membrane using an innovative yet simple and easy-to-implement surface

imprinting technology. We found that the resultant aquaporin-incorporated

biomimetic membrane allows water to pass through it faster and also display

lower salt leakage than a membrane without aquaporin."

Unlike conventional biomimetic membranes which tend to be quite fragile, the

novel membrane exhibits high mechanical strength and stability during water

filtration. This makes it suitable for industrial applications in water

treatment and desalination. For the public, this could mean greater supply of

drinking water at much lower costs in the near future.

The team is currently in discussions with an American-based company to develop

a pilot-scale module to test the feasibility of the membranes in the next two

years.

According to Assoc Prof Tong, the team's technique of producing the biomimetic

membranes can be applied in biological and biomedical research where the study

of any other biological membrane protein requires its unique characteristics

and functions to be expressed and properly placed onto synthetic membranes.

The team is also currently in discussions with AWAK Technologies to engineer

similar biomimetic membranes for wearable kidney dialysis devices. The future

wearable kidney dialysis machines may work without any adsorbents and may also

be much more compact in size.

More information about the research:

http://news.nus.edu.sg/press-releases/9790-biomimetic-membrane-for-water-purification

MEDIA CONTACT:

Amal Naquiah

National University of Singapore

DID: +65-6516-5125

Email: amal@nus.edu.sg

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SOURCE  National University of Singapore