Efficient and recycled magnetic self-stirring hollow fiber-solid/liquid phase system: An extraction and removal technique for personal care pollutants

Abstract

The removal of personal care products (PCPs) in aqueous environments is a huge challenge. Traditional powder and magnetic materials are not conducive to complete solid–liquid separation, which hinders their practical application. In this study, the convenient recyclable magnetic self-stirring system combining with n-octanol hollow fiber-liquid phase micro-extraction (HF-LPME), wormhole-like mesoporous carbon (WMC) solid phase and magnetic stirring was constructed to improve the extraction and removal efficiency of the trace PCPs (triclosan, triclocarban, 2, 2′-Dihydroxy-4-methoxybenzophenone, and 2, 4-dihydroxydiphenylketone) in wastewater. The adsorption process of triclosan and 2,2′-dihydroxy-4-methoxybenzophenone on the WMC surface followed the pseudo-first-order kinetics as well as Freundlich isotherm model. Because WMC had oxygen-containing groups and the multiple mesoporous distribution forming the n-octanol microextraction unit and the shearing strength generated by the stir bar in the water sample accelerated the mass transfer efficiency of PCPs, this system had the advantage of simultaneous removal and extraction of four PCPs from wastewater samples. The extraction mechanism involved the hydrophobic force and size effect between the WMC and PCPs. In addition, the factors affecting extraction efficiencies (EEs) were discussed, such as the concentrate of WMC (1 mg/L), rotation rate (400 rpm), extraction time (15 min), and salt concentration (30%). The results indicated that the method possessed a wide linear range (0.05–200 μg L-1), and lower limits of detection (LODs) (S/N = 3, 0.005–0.05 μg L−1), at the optimal conditions. This method also showed excellent reusability and stability, with higher recovery (88–98%) and fewer relative standard deviations (2.4–6.3%). This work not only minimized secondary pollution from powder adsorbents, but provided an economic and green magnetic self-stirring system and absorbent for the extraction, removal, and determination of typical PCPs pollutants from actual wastewater samples.