Goethite and magnetite modified whit fluorine supported onto biochar to adsorptive-photocatalytic removal of diclofenac and ibuprofen under simulated sunlight irradiation

ALVEAR-DAZA, JOHN J.; JULIÁN A. RENGIFO-HERRERA; LUIS R. PIZZIO

Buenos Aires

Congreso; WCCE11-11th World congress of Chemical Engineering. XXX Interamerican Congress of Chemical Engineering ? IACCHE; 2023

The composite materials based on photocatalysts naturally present in water matrices as magnetite (Fe3O4) and goethite (α-FeOOH) supported on biochar exhibit a potential synergistic effect on adsorption-photodegradation processes of pollutants. Moreover, the modification of metal oxides with fluoride can enhance their photocatalytic activities. In this study, it was explored the modification of goethite and magnetite by fluoride and their further immobilization onto biochar obtained from sunflower seed shells. The novel composite materials, fluorinated goethite, and magnetite (20% wt.) were in-situ generated onto the biochar surface and porous structure by a hydrothermal treatment at 80 ○C for 12 h in the presence of fluorine (1 mg L-1). The resulting materials were named BC-GoeF and BC-MagF, respectively. Composite materials were characterized by XRD, Mösbauer spectroscopy, XPS, DRS, and N2 adsorption-desorption. The adsorption-photocatalytic activity of composite materials was evaluated in the removal of diclofenac (DI, initial concentration of 2 mg L-1) and ibuprofen (IB, initial concentration of 2 mg L-1) under simulated sunlight irradiation (300 W m2) obtaining removals of 98%DI and 96%IB, 93%DI and 96%IB with BC-GoeF and BC-MagF (composite amounts of 0.5 g L-1) respectively, after 5 h of irradiation in presence of 10 mg L-1 of H2O2. The results demonstrated that the presence of fluorinated goethite, and magnetite onto biochar could enhance the photodegradation of pharmaceuticals through the generation of reactive oxygen species as the hydroxyl radical (•OH) under simulated solar light irradiation. Thus, pharmaceuticals compounds would not be only adsorbed onto biochar but also their degradation could be achieved due to the presence of photoactive fluorinated iron oxides (hydr) oxides.