Preparation and Characterization of Magnetically Responsive Biosorbents from Coffee Industry Residues

摘要

Spent coffee grounds (SCG) and coffee silverskin (CS), the two main coffee industry residues, were magnetically modified by contact with an aqueous ferrofluid containing magnetite nanoparticles. The materials were characterized by SEM-EDX analysis, X-ray diffraction and FTIR spectroscopy. Batch adsorption experiments were performed to assess their suitability as biosorbents, using methylene blue as a model pollutant. Adsorption equilibrium data were analysed by the Langmuir model, which allowed estimation of the maximum adsorption capacity. The magnetic biosorbents were easily regenerated by treatment with hydrochloric acid.