Perfluoroalkyl substances (PFAS), nicknamed "forever chemicals," pose a growing environmental and health threat. Since the invention of Teflon in 1938, PFAS and perfluorinated polymers or PFs have been widely used for their exceptional stability and resistance to water and heat.

A room-temperature defluorination method proposed by researchers at Ritsumeikan University could revolutionize PFAS treatment

  • @A_A
    1•1 month ago

    … using cadmium (also toxic) :
    “The proposed method involves irradiating visible LED light onto cadmium sulfide (CdS) nanocrystals and copper-doped CdS (Cu-CdS) nanocrystals with surface ligands of mercaptopropionic acid (MPA) in a solution containing PFAS, FPs, and triethanolamine (TEOA).”

    • @BellOP
      2•1 month ago

      I think elemental cadmium is toxic, I’m not sure CdS is. It is used in many many light detecting circuits. I think the CdS is used as a catalyst here anyway, so not depleted in use.

      • @A_A
        1•1 month ago

        CdS is insoluble in pure water, yet :

        Cadmium sulfide is toxic, especially dangerous when inhaled as dust, and cadmium compounds in general are classified as carcinogenic. (…) https://en.m.wikipedia.org/wiki/Cadmium_sulfide

        ideally you will hope to have a process in which this powder will be supported on a stable substrate … but eventually, if you don’t use pure water, any impurity can have any chemical composition … so, if you are working in the real world with a mix of unknown soup, you will end up with chemical reactions … especially if there is some acids you will leach out the cadmium as soluble compounds or you may get fragmentation and powder coming out, going to the environment, pickied up by wind, creating dust in the air (…) .

        Still, the process might be viable if well controlled and if the gain by eliminating PFAS is great enough.

        P.S. this process involves liberation of fluoride so you will get :
        Cadmium fluoride : Solubility in water 4.35 g/100 ml https://en.m.wikipedia.org/wiki/Cadmium_fluoride