Rapid and efficient removal of organic micropollutants from environmental water using a magnetic nanoparticles-attached fluorographene-based sorbent

Abstract

Organic micropollutants (OMPs), including both regulated and emerging contaminants, have been extensively detected in ground and surface waters, posing hazards to organisms and humans. Rapid and efficient removal of OMPs from environmental water by novel sorbents is still faced with severe challenges. Here we developed a magnetic nanoparticles-attached fluorographene-based (MNPs@FG) sorbent with high affinity to OMPs such as perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS) compared to powdered activated carbon, the most widespread sorbent for OMPs removal. The removal efficiencies of PFOA and PFOS using the MNPs@FG sorbent were systematically examined at room temperature. The MNPs@FG sorbent showed 92–95% and 94–97% removal efficiencies of PFOA (180 μg/L) and PFOS (180 μg/L) in 2 min respectively, with relatively high sorption capacities for PFOA (50.4 mg/g) and PFOS (17.2 mg/g). The adsorption performance was stable even in the presence of natural organic matter. Moreover, the MNPs@FG sorbent could notably reduce PFOA and PFOS from ∼5 μg/L (an environmentally relevant concentration) to <50 ng/L in environmental water, lower than the U.S. Environmental Protection Agency health advisory level (70 ng/L). Besides PFOA and PFOS, the MNPs@FG sorbent also showed high removal efficiencies (97–99%) of difloxacin hydrochloride (DIF), acetochlor (ACE) and chlorantraniliprole (CHL) in short time (e.g. 10 min). The used MNPs@FG sorbent was facilely regenerated by methanol washing and reused five times without reduction in PFOA/PFOS removal and magnetic performance. Thus, this study provided a novel sorbent for rapid and effective removal of OMPs from environmental water.