Facile Synthesis and Reuse of Magnetic Black Carbon Magnetite (BC-Mag) for Fast Carbamazepine Removal from Water.

Magnetic carbonaceous nanomaterials are needed in water treatment applications because they can offer both carbon surfaces for sorption of organic pollutants and ease of material magnetic retrieval for regeneration and reuse. In this study, we employed a facile one-step method to synthesize a black carbon-magnetite composite (BC-Mag) by high-temperature annealing of black carbon and hematite. The nanocomposite was easily dispersed and stable in water owing to the presence of negatively charged oxygen surface functional groups. Sorption kinetics with dissolved carbamazepine showed a rapid initial uptake with equilibrium achieved within only minutes. The sorption extent can be described with the Freundlich model, and surface area normalized sorption affinity was an order of magnitude greater than conventional granular activated carbon. The sorption extent of neutral carbamazepine remained constant between pH 2-10 while surface zeta potential decreased. BC-Mag can be reused for the sorption of carbamazepine up to six times without significant loss of the sorption extent.