There is a lot hidden in "will be filtered out" here though.
Filtration isn't binary, so this may only be useful in a few target areas where water sources are contaminated enough that introducing a new contaminate (these NPs) into the water will pull out more PFAS than are left behind after magnetic separation.
The NPs (or more likely the PFAS that degrade off of the Fe3O4) also may have a different health affect than PFAS in the water stream (due to sulfonation etc).
So it's certainly not that simple, but a great technology for companies trying to recover their chemical products and reactants for reuse and for areas where contamination is very bad.
Filtration isn't binary, so this may only be useful in a few target areas where water sources are contaminated enough that introducing a new contaminate (these NPs) into the water will pull out more PFAS than are left behind after magnetic separation.
The NPs (or more likely the PFAS that degrade off of the Fe3O4) also may have a different health affect than PFAS in the water stream (due to sulfonation etc).
So it's certainly not that simple, but a great technology for companies trying to recover their chemical products and reactants for reuse and for areas where contamination is very bad.