Fei Wang, Kai Min Shih, Xiao Yan Li, The partition behavior of
perfluorooctanesulfonate (PFOS) and perfluorooctanesulfonamide (FOSA) on
microplastics, Chemosphere, Volume 119, January 2015, Pages 841-847,
ISSN 0045-6535, http://dx.doi.org/10.1016/j.chemosphere.2014.08.047.
(http://www.sciencedirect.com/science/article/pii/S0045653514010200)
Abstract: Microplastics have been recognized as transport vectors for
heavy metals and organic pollutants to marine animals. Thus, the
sorption behavior of contaminant on microplastic is crucial to their
transport in marine system. In this study, the sorption behavior of PFOS
and FOSA (two perfluorochemicals) on three kinds of microplastics (PE,
PS, and PVC) are reported. The isotherm study showed that the sorption
of PFOS and FOSA on microplastics is highly linear, and it indicated
that partition by hydrophobic interaction is the predominant sorption
mechanism. The Kd values of FOSA on three kinds of microplastics are all
higher than those of PFOS, and the reason is attributed to their
different functional groups. The Kd value of FOSA on three types of
microplastics followed the order as: PE > PVC > PS. Such finding may
indicate that the molecule composition and structure of microplastics
play important roles in their sorption processes of organic pollutants.
The PFOS sorption levels on PE and PS particles were increased with the
increase of NaCl and CaCl2 concentrations, while the ion concentrations
have no effect on FOSA sorption. The study on the pH effects on PFOS and
FOSA sorption indicated FOSA could partition under various pH conditions
on three types of microplastics while PFOS sorption on PE and PS were
favored with lower pH.
Keywords: PFOS; FOSA; Sorption; Partition; Electrostatic interaction