Iron Oxide Nanoparticles Supported on Mesoporous MCM-41 for Efficient Adsorption of Hazardous β-Lactamic Antibiotics

• Published in: Water, air, and soil pollution Vol. 229; no. 3; pp. 1 - 14
• Main Authors: Salviano, Adriana Barbosa, Santos, Mariana Rocha Dutra, de Araújo, Laura Maia, Ardisson, Jose Domingos, Lago, Rochel Montero, Araujo, Maria Helena
• Format: Journal Article
• Language: English
• Published: Cham Springer International Publishing 01-03-2018; Springer Nature B.V
• Subjects: Adsorption; Amoxicillin; Antibiotics; Atmospheric Protection/Air Quality Control/Air Pollution; Ceftriaxone; Cephalexin; Climate Change/Climate Change Impacts; Crystal defects; Crystallization; Defects; Earth and Environmental Science; Environment; Environmental monitoring; Haematite; Hematite; High temperature; Hydrogen peroxide; Hydrogeology; Iron; Iron oxides; Nanoparticles; Penicillin; Phosphates; Soil Science & Conservation; Surface chemistry; Water Quality/Water Pollution; Iron oxide; MCM-41; Adsorption; Amoxicillin
• ISSN: 0049-6979; 1573-2932
• DOI: 10.1007/s11270-017-3652-6

In this work, the effect of crystallite size, defects, and surface area of iron oxyhydroxide particles supported on mesoporous MCM-41 on the adsorption of hazardous β-lactamic antibiotics was investigated. Different adsorbents were prepared by impregnation of 5, 10, 20, and 50 wt% of Fe followed by treatment at 150–400 °C. Mössbauer, XRD, BET, TG, FTIR, and Raman analyses suggested that treatment at 150 °C produced a mixture of α-Fe
2
O
3
, FeOOH, and highly dispersed Fe
3+
species. At higher temperatures, different phases were gradually converted to hematite with crystallite sizes varying from 1 to 5 nm. Both, Fe content and temperature, strongly affected the amoxicillin, cephalexin, and ceftriaxone adsorption at pH 5, 7, and 9, with the best results obtained for the sample 20Fe150 (20% Fe treated at 150 °C), ca. 25 mg
AMX
 g
−1
which decreased to 17, 6, and 4 mg
AMX
 g
−1
(AMX = amoxicillin) upon treatment at higher temperatures. These results combined with competitive adsorption using AMX/phosphate and H
2
O
2
decomposition experiments suggested that the antibiotic molecules are likely adsorbing by complexation on Fe
3+
surface species of poorly crystallized small particles of Fe oxyhydroxide phases. It was observed that below a critical crystallite size of 3 nm, the AMX adsorption was very sensitive and strongly increased.