- Dale Allen
Researchers Produce Safer Solvent for Removing Metals from Water
Updated: May 4, 2020
Solvents have been in use for many years across a wide range of industries. Most of the products that we use every day are created using solvents in the production process.
This includes chemical manufacture, obviously, but also your daily food and beverages.
All of these industries and more use solvents in their production processes
Food and beverages,
paints and coatings,
cosmetics and personal care items,
dyes and pigments,
and yes, even pharmaceuticals, among others.
Solvents are everywhere and they're usually pretty damaging to the environment and can cause some severe illnesses in humans.
However, they're just too useful for us to stop using them
Unfortunately, their use to remove specific metals from water have some pretty big disadvantages. The safety risks are very high, they're expensive and they're bad for the environment.
So, over the years there have been calls to produce a cleaner, greener solvent that can be used for the removal of metals in water and there have been several attempts, all of which were unsuitable due to those solvents being easily dissolved in the water.
However, recently a group of researchers at the Eindhoven University of Technology (TU/e) have actually produced a water-resistant solvent.
Carin Dietz, Adriaan van den Bruinhorst, Dannie van Osch, Dries Parmentier, Remco Tuinier and Maaike Kroon published their results in the Chemical Communications science journal and they show a much cheaper, safer and environmentally friendly product that successfully absorbs the metals and then separates itself from the water.
What they created is called a hydrophobic deep eutectic solvent (DES) which is part of a newly discovered category of solvents and they claim that it can remove heavy metals like iron or nickel in a matter of seconds.
The process is very simple
To remove the metals from the water they simply mix it with their solvent and strongly shake the mixture. The solvent absorbs the metals and, because it's water-resistant, it simply floats to the top once the shaking has stopped, taking its pollutants with it.
And the most important part here is that this new solvent vapourises only a very small amount and is therefore significantly safer than the organic solvents currently in use.
Unfortunately, the researchers expect at least another decade of research to be undertaken before an industrial version of this solvent is available on shelves.
This is because their solution doesn't remove enough of the metal salt from water.
Metal presence in water is generally in a metal salt form, cobalt chloride, which breaks down into metal cobalt ions and chloride. Their solvent removes the entirety of the cobalt ions but leaves some of the chloride behind.
If you would like to learn more about the dangers of heavy metals in water and the correct control measures to use in a laboratory you can take the new COSHH Risk Assessor Certification™.