New Filtration Technology Could Be Gamechanger In Removal of PFAS 'Forever Chemicals' (theguardian.com) 4
Bruce66423 shares a report from the Guardian: New filtration technology developed by Rice University may absorb some Pfas "forever chemicals" at 100 times the rate than previously possible, which could dramatically improve pollution control and speed remediations. Researchers also say they have also found a way to destroy Pfas, though both technologies face a steep challenge in being deployed on an industrial scale. A new peer-reviewed paper details a layered double hydroxide (LDH) material made from copper and aluminum that absorbs long-chain Pfas up to 100 times faster than commonly used filtration systems.
[...] [Michael Wong, director of Rice's Water Institute, a Pfas research center] said Rice's non-thermal process works by soaking up and concentrating Pfas at high levels, which makes it possible to destroy them without high temperatures. The LDH material Rice developed is a variation of similar materials previously used, but researchers replaced some aluminum atoms with copper atoms. The LDH material is positively charged and the long-chain Pfas are negatively charged, which causes the material to attract and absorb the chemicals, Wong said. [...]
Pfas are virtually indestructible because their carbon atoms are bonded with fluoride, but Rice found that the bonds could be broken if the chemicals in the material were heated to 400-500C -- a relatively low temperature. The fluoride gets trapped in the LDH material and is bonded to calcium. The leftover calcium-fluoride material is safe and can be disposed of in a landfill, Wong said. The process works with some long-chain Pfas that are among the most common water pollutants, and it also absorbed some smaller Pfas that are commonplace.
Wong said he is confident the material can be used to absorb a broad array of Pfas, especially if they are negatively charged. Most new Pfas elimination systems fail to work at an industrial scale. Wong said the new material has an advantage because its absorption rate is so strong, it can be used repeatedly and it is in a "drop in material," meaning it can be used with existing filtration infrastructure. That eliminates one of the major cost barriers.
[...] [Michael Wong, director of Rice's Water Institute, a Pfas research center] said Rice's non-thermal process works by soaking up and concentrating Pfas at high levels, which makes it possible to destroy them without high temperatures. The LDH material Rice developed is a variation of similar materials previously used, but researchers replaced some aluminum atoms with copper atoms. The LDH material is positively charged and the long-chain Pfas are negatively charged, which causes the material to attract and absorb the chemicals, Wong said. [...]
Pfas are virtually indestructible because their carbon atoms are bonded with fluoride, but Rice found that the bonds could be broken if the chemicals in the material were heated to 400-500C -- a relatively low temperature. The fluoride gets trapped in the LDH material and is bonded to calcium. The leftover calcium-fluoride material is safe and can be disposed of in a landfill, Wong said. The process works with some long-chain Pfas that are among the most common water pollutants, and it also absorbed some smaller Pfas that are commonplace.
Wong said he is confident the material can be used to absorb a broad array of Pfas, especially if they are negatively charged. Most new Pfas elimination systems fail to work at an industrial scale. Wong said the new material has an advantage because its absorption rate is so strong, it can be used repeatedly and it is in a "drop in material," meaning it can be used with existing filtration infrastructure. That eliminates one of the major cost barriers.