Effects of fluorescent dissolved organic matters (FDOMs) on perfluoroalkyl acids (PFAAs) in lake and river water

This study presents the effects of fluorescent dissolved organic matters (FDOM) on perfluoroalkyl acids (PFAAs) in western Lake Chaohu and its inflow rivers. The surface water samples from the 27 sites in western Lake Chaohu and its inflow rivers were collected in March and September 2013. The contents of PFAAs and the FDOM in the water samples were measured by a high-performance liquid chromatograph - mass spectrometer (HPLC-MS) and by a fluorescence spectrophotometer, respectively. The temporal-spatial distributions of PFAAs and FDOM, as well as their interrelationships, were investigated. Eleven PFAA components were detected, and the mean concentration of total PFAAs (TPFAAs) in western Lake Chaohu and its inflow rivers were 12.93 +/- 5.19 ng/L and 11.84 +/- 950 ng/L, respectively. PFOA was the predominant contaminant in two regions (7.13 +/- 3.07 ng/L and 430 +/- 2.14 ng/L) followed by PFHxA (172 +/- 0.80 ng/L and 1.42 +/- 1.41 ng/L) and PFBA (1.44 +/- 078 ng/L and 1.37 +/- 0.78 ng/L). The mean concentration of total FDOM in western Lake Chaohu and its inflow rivers were 220.0 +/- 4030 mu g quinine sulfate units (Q.S.)/L and 406.3 +/- 213.1 mu g Q.S./L, respectively. The significant, positive correlations were observed between the PFAAs and FDOMs in both the lake area and the inflow rivers. However, no significant correlation was observed between PFAAs and the dissolved organic carbon (DOC) in the lake area. This finding indicated that the residues and distributions of PFAAs were significantly dependent on the compositions of dissolved organic matters (DOM) and not on the total content of DOM. (C) 2019 Elsevier B.V. All rights reserved.