Good Thinking

Wood could clean up in the world of water purification

Wood could clean up in the wor...
Water is filtered using the cellulose-based system
Water is filtered using the cellulose-based system
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Water samples before (right) and after filtration using the new technology
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Water samples before (right) and after filtration using the new technology
Water is filtered using the cellulose-based system
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Water is filtered using the cellulose-based system

Oftentimes, the places that require water purification the most – such as developing nations or disaster sites – have the least in the way of infrastructure. This means that electrically-powered systems can't be used, while technology utilizing materials such as silver may be too costly. Help could be on the way, however, in the form of water filters made from wood.

Developed by a team led by Prof. Monica Ek at Sweden's KTH Royal Institute of Technology (where other interesting things have been done with wood), the filters more specifically incorporate wood-derived cellulose fibers.

These fibers not only trap suspended particles, but they're also coated in a positively-charged polymer. Because bacteria and viruses are negatively-charged, they're attracted to the polymer and then get stuck on it as the water is being filtered. They subsequently die while trapped there, unable to reproduce.

Once the filters are full, they can simply be pulled out, dried and burned.

Water samples before (right) and after filtration using the new technology
Water samples before (right) and after filtration using the new technology

Not only does the filtration system not require electricity or expensive materials, but it also doesn't release toxic compounds into the environment, plus microbes can't build up a resistance to it. Given these selling features, the technology may also find its way into applications such as bandages and food packaging.

This isn't the first time we've heard of wood being used to purify water. In 2014, a team from MIT reported that the tiny membranes within pine sapwood could remove approximately 99 percent of bacteria from tainted water.

Source: KTH Royal Institute of Technology via AlphaGalileo

1 comment
myale
Bit sparse on technical details - flow rates, pressures, capacities would be interesting