Comment on 'In situ air-water and particle-water partitioning of perfluorocarboxylic acids, perfluorosulfonic acids and perfluorooctyl sulfonamide at a wastewater treatment plant [Vierke et al. Chemosphere 2013 doi: 10.1016/j.chemosphere.2013.02.067]'

摘要

In their article, Vierke et al. (2013) report on air-water and particle-water partitioning of perfluorocarboxylic acids, perfluorosulfonic acids and perfluorooctyl sulfonamide at a wastewater treatment plant, and employ this data to make inferences regarding the acid dissociation constant (pK_a) of n-perfluorooctanoic acid (n-PFOA). The authors fail to cite several studies (Cheng et al., 2009; Rayne and Forest, 2010a; Kutsuna et al., 2012) which collectively and unequivocally indicate that the pK_a of n-PFOA is not 3.8 as claimed by Burns et al. (2008), but is instead likely in the range of about 0 to +1.