Abstract
Adsorption removal of eight per-fluorinated compounds by powdered activated carbon was studied. In single-solute solutions, adsorption equilibrium constant K were calculated as 22.33 for PFOS, and 14.48 for PFOA. Substances with longer carbon chain were removed better, suggesting the relation of adsorption removal with their hydrophobicities. In mixed solution of the eight compounds, the removed amount of three compounds: PFDA, PFDoA, and PFOS was decreased to 80 % of single-solute solution, whereas for the other five: PFHxA, PFHpA, PFOA, PFNA, and PFHxS, the amount decreased to less than half. The effect of dissolved organic matters was also investigated by using Lake Biwa water as the solvent of the mixed solution. The removal of PFOS and PFHxS was not greatly affected and the removed amount decreased by 60%. However, the other five compounds were scarcely removed, showing irregular temporal concentration changes.
