Synthesis of superparamagnetic activated carbon for paracetamol removal from aqueous solution

The present work reports the preparation and characterization of superparamagnetic activated carbons (SPACs) for paracetamol (PCT) removal from aqueous solution. The SPACs were synthesized from co-precipitation method, producing Fe3O4 nanoparticles over the surface of a super activated carbon (SAC) in weight ratios SAC/Fe3O4 of 1:1, 1:2 and 1:3. The textural characterization revealed the SPACs have micro and mesoporous, besides high values of BET surface area. According to Mossbauer spectroscopy and VSM curves, non-stoichiometric Fe3O4 is the main magnetic phase over the surface of the materials, presenting a superparamagnetic behavior. The adsorption study showed the maximum adsorption capacity occurs at pH < pH(PZC), and the kinetic model of pseudo-second order and equilibrium model of Freundlich were that better fitted the experimental data. The obtained results contributed to comprehend the corrosion inhibiting effect caused by PCT molecules on SPACs' surfaces. From the characterization results and adsorption assays, an adsorption mechanism was proposed. (C) 2019 Elsevier B.V. All rights reserved.