The scope of our study was to prepare Fe-based highly active catalysts for water treatment processes. The reactive nanomaterials were
synthesized by chemical precipitation; the post-synthesis coating of the as obtained nanostructures was achieved by capping the magnetic cores with a
polymeric surfactant, polyethylene glycol (PEG). The resulted Fe3O4/PEG nanoparticles were further used to immobilize two types of reactive materials on
their surface, either ferrous oxalate (FO) or ferric citrate (FC), yielding the final products – two green Fenton-like heterogeneous nanocatalysts. The
sensitized catalysts were characterized by several microstructure characterization techniques such as X-ray diffraction (XRD), vibrating sample
magnetometry, BET, scanning electron microscopy (SEM), and energy dispersive X-ray spectroscopy (EDX). All experiments were performed on a
laboratory scale set-up. Important variables such as effect of hydrogen peroxide concentration, UV light, the amount of catalyst and contact time for the
catalytic wet peroxide oxidation (CWHPO) of BPA were examined. The results indicate that the oxidation rate increased under UV light in the presence of
low-concentration H2O2.
Two types of surface modified magnetite (Fe3O4) nanoparticles, coated with either tannic acid (TA) or dissolved natural organic matter (NOM), were evaluated as magnetic heterogeneous catalysts. Simple and efficient procedures for the synthesis of the magnetic catalysts were employed, their properties being fully assessed by various characterization techniques. The catalytic activity in heterogeneous oxidation of aqueous solutions containing Bisphenol A (BPA) over the catalysts was comparatively studied. The optimum experimental parameters were: 1g/L of catalysts, 10 mM H2O2, under UV irradiation. The highest mineralization rates were observed for Fe3O4-TA catalyst. More than 80% of BPA were removed after 30 minutes of reaction time under the specified experimental conditions. The results showed that the obtained catalysts are suitable candidates for the removal of pollutants in wastewaters by means of heterogeneous reaction
The use of magnetic materials as heterogeneous catalysts has attracted increasing attention in the last years since they proved to be promising candidates for water treatment. In the present study, two types of surface-modified magnetite (Fe3O4) nanoparticles, coated with non-hazardous naturally occurring agents—either tannic acid (TA) or dissolved natural organic matter—were evaluated as magnetic heterogeneous catalysts. Chemical synthesis (co-precipitation) was chosen to yield the nanocatalysts due to its well-established simplicity and efficiency. Subsequently, the properties of the final products were fully assessed by various characterization techniques. The catalytic activity in heterogeneous oxidation of aqueous solutions containing a model pollutant, Bisphenol A (BPA), was comparatively studied. The effect of operational parameters (catalyst loading, H2O2 dosage, and UV light irradiation) on the Degradation performance of the oxidation process was investigated. The optimum experimental parameters were found to be 1.0 g/L of catalysts and 10 mM H2O2, under UV irradiation. The highest mineralization rates were observed for Fe3O4-TA catalyst. More than 80 % of BPA was removed after 30 min of reaction time under the specified experimental conditions. The obtained results showed that the two catalysts studied here are suitable candidates for the removal of pollutants in wastewaters by means of heterogeneous reaction using a green sustainable treatment method.