Diffusiophoresis – don’t be put off

According to The Economist magazine on 20th May, based on research by Princeton University and published in Nature Communications, this could be the solution to many of the world’s problems with water access and quality.

It’s only at an experimental stage, but the test was remarkably successful. It:

• removed 99.95% of particles
• used under one thousandth of the energy required for membrane filtration
• is cheap and should prove easy to maintain
• only requires carbon dioxide.

My explanation may not be sufficient, but essentially the process involves:

• a flow of water with
• gas permeable membranes on either side,
• one containing carbon dioxide and
• one containing air.

As the carbon dioxide moves from one side to the other, the positively charged particles gravitate towards it and the negatively charged particles gravitate towards the air, leaving the main flow clean.

We may well hear more about diffusiophoresis.