New Defective Water Filter Helps Remove Toxic Chemicals

Nowadays, many researchers are looking for a way to remove chemicals in wastewater from industrial usage more effectively. But then they found the solution in a counter-intuitive way: just use a defective water filter.

A More Porous Water Filter?

Coming from Texas Rice University, a group of researchers has just announced a weird new type of water filter. Because it is not as perfect as the previous ones. But somehow it is very good at absorbing chemicals in wastewater.

In a recent article on the ACS Sustainable Chemistry and Engineering of American Chemical Society, the team under the leadership of the two head scientists Chelsea Clark and Michael Wong at Rice University has shown that considering absorbing PFOS (perfluorooctanesulfonic acid), non-porous isn't the only or best answer.

The team has developed an innovative kind of nanomaterial highly-porous filter comes under the name of MOF (metal-organic framework). This MOF is capable of absorbing PFOS in wastewater much faster than the previous kinds of filters. In this water filter, they have also applied the new nanometer-sized holes (usually considered as defects) into the material of the filter. They figured out that these holes would help the MOF hold even more PFOS.

Perfluorooctanesulfonic Acid

So we need to understand more about PFOS ( perfluorooctanesulfonic acid ). First, it is a very common chemical that is used in the industrial process to produce consumer products like stain-resisting fabrics, carpeting... It is highly toxic to the human body and it belongs to the family of PFAS (polyfluoroalkyl substances )

US Environmental Protection Agency has introduced the policy to restrict this toxic chemical which they describe as very persistent and hard to remove out of the human body and the environment. PFOS has been the subject of many lawsuits in the US alone.

Metal-Organic Frameworks

According to Michael Wong, MFOs is a three-dimensional structure that is made of organic molecules and metal ions, the whole structure can self-assemble when the two interact.

Those two materials can develop into very complicated structures which are highly porous. That is why Wong think MOFs is a good choice for filter PFOS.

For example, MOFs has been proven to be very effective in capturing targeted molecules and also could hold them for a long period. Just for a single gram of MOFs, we have a total surface of more than a football field.

Moreover, the structure, functions, pore sizes of the MOFs as a defective filter could be changed with synthesis to target another kind of pollutants.