Polyaromatic hydrocarbons are commonly formed during incomplete combustion under improper conditions. They spread through the environment bound to flying ash without significant natural decomposition, and some of them are proven carcinogens. For treatment of such contaminated water, we have chosen the method of extraction by a magnetic sorbent. The dangerous substances can be captured on the sorbent’s surface and effectively removed by a magnetic field. The synthesis process begins with the crystallization of magnetite cores (Fe3O4) several nanometers in diameter to obtain a large surface on which polyaromatics can be adsorbed. These cores were then covered by a layer of silica gel to ensure the stability of the material and the possibility to attach other functional groups. Due to the nature of target substances, a C18 hydrocarbon chain was chosen on which non-polar polyaromatics should be captured. To verify the success of the synthesis, several analytical techniques were involved. Subsequently, the removal efficiency of 16 representative polyaromatic compounds from water was tested. More than 90% removal was achieved within ten minutes at doses around 5 g/l. The conclusions formulated based on the experimental data were supported by computer modelling of PAH capture on the C18 chain. The successful preparation of a magnetic sorbent and its suitability for a given purpose was proved.
D. Pilnaj, P. Kuráň, M. Šťastný, V. Pilařová, P. Janoš, M. Kormunda, J. Tokarský. C18-functionalized Fe3O4/SiO2 magnetic nano-sorbent for PAHs removal from water. Environmental Technology and Innovation 24 (2021) 101905