Our waterways are becoming more and more polluted due to PFAS, plastics, medicines, drugs, and new chemicals made by companies that just hand over the responsibility of cleaning to plants paid for by public moneys. Detecting the different chemicals and filtering them out if getting harder and harder. Could the simple solution of heating up past a point where even PFAS/forever chemicals decomposes (400C for PFAS, 500C to be more sure about other stuff) be alright?

  • specialseaweed@sh.itjust.works
    0·
    3 days ago

    No. The far more likely way to handle it is with flocculation/coagulation since plants are already set up to support this.

    Edit: the quick and dirty overview: shit water comes in. Chlorine and other chemicals are added to the water which kills the bad stuff. Polymers are added to the water which binds to the chlorine, causing chunks. Chunks removed. Water discharged. You can change the polymers used to bind specifically to which pollutant is coming in.

    That part of the process is called flocculation. Using it to add polymers that have additional capability (like removing microplastic) is where you’d want to do it. The cost is the polymer which would be some sort of reasonable, not rebuilding every plant that exists to boil water.

    Check out the video on the flocculation page. Does a great job of showing how floc works.

    https://en.m.wikipedia.org/wiki/Flocculation

    https://en.m.wikipedia.org/w/index.php?title=Wastewater_treatment&wprov=rarw1

    • Waterdoc@lemmy.ca
      1·
      3 days ago

      For simplicity, this process is called clarification.

      Unfortunately, coagulants are not effective at removing PFAS. The only effective methods for PFAS removal are adsorption (using granular activated carbon or ion exchange resins) or reverse osmosis filtration. These approaches are not used in traditional wastewater treatment because they are very expensive and are not required to meet registrations. However, potable reuse facilities will use these approaches to further treat wastewater effluent to drinking water standards. This is the future of water supply for arid areas like the southwest USA.

      Also PS, the most commonly used coagulants are aluminum sulphate (alum) and ferric sulphate, which are not polymers. Polymers definitely are used (especially where I live) but they are more expensive and thus avoided when not needed.