Fe Oxides–Eggshell Composites: Development, Characterization, and Oxytetracycline Adsorption Test

ORIANA LOPEZ; MARIELA FERNANDEZ; MANUEL HORUE; FLORENCIA URRUCHUA; HILDA CORREA; LING XIA; MARIA EMILIA ZELAYA SOULE

Arabian Journal for Science and Engineering

Springer Nature

Año: 2024

While emerging pollutants are being detected in water bodies globally, a significant amount of solid waste that could beused for effluent remediation is being discarded. This not only reduces the half-life of landfills but also contributes toenvironmental pollution. Of these, eggshells (ES) are one of the most discarded food waste items worldwide. This paperpresents the development and characterization of ES-based adsorbent for the removal of oxytetracycline (OTC), an emergingpharmaceutical pollutant, from aqueous solutions. The sorption of OTC on ES and ES-derived materials has not been previouslystudied. The ES was modified by removing the organic layer and both materials were used to grow Fe oxides, which can impartmagnetic response to allow indirect manipulation or the addition of new sorption sites. Two methodologies were employedto synthesize Fe oxides: alkaline oxidation in the presence of nitrate and impregnation–pyrolysis (IP), which have not beenused previously for developing magnetic ES. The materials developed by IP exhibit the highest total specific surface areaand display a magnetic response due to the presence of magnetite and maghemite. Moreover, they exhibit a negative zetapotential over a wide range of pH values. All materials were able to adsorb OTC at pH 3, 7, or 9, indicating that ES (thesimplest material) and ESIP (composite with good enough magnetic response) are suitable for removing OTC from aqueoussolution. ES is recommended when indirect manipulation is not necessary, whereas ESIP is recommended when it is required.In order to explore the potential for reuse of the composite-pollutant materials, their antibacterial capacity against E. coli andE. faecium was evaluated. The findings of the present work contribute to the development of a circular economy by reducingwaste generation, minimizing the consumption of natural resources, and reducing greenhouse gas emissions, while improvingenvironmental protection