Natural and artificial radionuclides in sludge, sand, granular activated carbon and reverse osmosis brine from a metropolitan drinking water treatment plant

- 40K showed the highest specific activities in sludge, sand and RO brine.
- 238U showed the highest specific activities in GAC.
- Medically-derived 131I was quantified in sludge, sand and GAC.
- 238U, 210Pbu, 7Be and 137Cs showed the highest variabilities in sludges (RSD>29%).
- 238U accumulation was correlated with the progressive efficiency loss in GAC.