In-situ magnetization of porous carbon beads by pyrolysis of waste red mud doped polysulfone beads for efficient oil sorption

Abstract

This study describes for the first time the preparation of in-situ magnetic porous carbon beads (MPC beads) through simple phase inversion and subsequent pyrolysis of red mud doped polysulfone beads. Red mud, which is the main industrial waste resulted from the aluminium production, contains an important amount of Fe2O3. Characterization studies demonstrated the in-situ carbo-reduction of Fe2O3 species into magnetic Fe3O4 thanks to polysulfone carbon source, involving then the synthesis of MPC beads. Owing to hydrophobic surface and macroporous structure, the MPC beads were evaluated on the sorption of various oils, including gasoline, diesel oil, mineral oil and olive oil from water. The maximum sorption capacity of the MPC beads for examined oils were determined as olive oil (2.018 ± 0.162 g/g)>mineral oil (1.418 ± 0.138 g/g)> diesel oil (1.316 ± 0.062 g/g)>gasoline (1.235 ± 0.028 g/g). Moreover, the MPC beads were regenerable by heat treatment and there was no change in their sorption capacities in the first ten consecutive sorption-desorption cycles. Consequently, the suggested approach on the pyrolysis of waste red mud doped polysulfone beads was successful at preparing in-situ MPC beads, which can be efficiently used for oil spills clean-up from water with easier separation by a magnet.