Magnetic hybrid gels for emulsified oil adsorption: an overview of their potential to solve environmental problems associated to petroleum spills

SCHEVERÍN, NATALIA; FOSSATI, ANA; HORST, FERNANDA; LASSALLE, VERÓNICA; JACOBO, SILVIA

ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH

SPRINGER HEIDELBERG

Lugar: HEIDELBERG; Año: 2019 vol. XX p. 1 - 12

0944-1344

Hydrogels (HGs) based on gelatin and crosslinked with gum Arabic have been prepared by the thaw?freezing method,employing two different concentrations of gum Arabic (15 and 50% w/w). Magnetic gels or ferrogels (FGs) were prepared byapplying the breath in method to incorporate iron oxide magnetic nanoparticles to the HG matrix. The obtained HG and FG werecharacterized by XRD, FTIR, and SEM, and the FG composition was estimated by atomic absorption spectroscopy in terms of Fecontent. The adsorption of crude oil onto HG and FG was explored achieving very satisfactory results. FG was regenerated bywashing with toluene, maintaining efficiency of almost 90% after the fourth cycle. Equilibrium studies were performed todetermine the capacity of the prepared FG for adsorption of crude oil from seawater synthetic solutions. The experiments werecarried out as a function of different initial concentrations of oil residue (24 to 240 mg/L) exploring different contact times.Equilibrium data were found to fit very well with the Sips models. The kinetic data adsorption of oil onto the FG-15 was betterfitted by a pseudo-second-order kinetic indicating that at the initial stages of adsorption, external mass transfer could control thewhole rate of the crude oil uptake while intraparticle diffusion controlled the global rate of adsorption at later stages. The obtainedresults showed that the FG prepared by employing 15% of gum Arabic as the crosslinker (FG-15) has a high removal efficiencyof crude oil reaching 1.53 g/g of FG at pH 5.5 and 0.59 g/g for oil/water emulsions in the order of 0.1 g/L. The magneticproperties extend its application. The reached data suggest that the materials presented here may be useful to further the design ofsystems or devices intended for the remediation of petroleum spills and/or its derivatives in marine water as well as other surfacessuch as polluted rocks or soil.