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2017 Publications

Chemosphere
Volume 175, May 2017, Pages 8-20

Enhancement of the adsorption capacity of the light-weight expanded clay
aggregate surface for the metronidazole antibiotic by coating with MgO
nanoparticles: Studies on the kinetic, isotherm, and effects of environmental

parameters

Ebrahim MohammadiKalhori, Tariq J.Al Musawi, EsmaeilGhahramani, HosseinKazemian,
MansurZarrabi

The synthesized MgO nanoparticles were used to coat the light-weight expanded clay
aggregates (LECA) and as a metronidazole (MNZ) adsorbent. X-ray diffraction (XRD),
scanning electron microscopy (SEM), transmission electron microscopy (TEM), and Fourier-
transformed infrared (FTIR) techniques were employed to study the surface morphology and
characteristics of the adsorbents. MgO/LECA clearly revealed the advantages of the
nanocomposite particles, showing high specific surface area (76.12 m2/g), significant
adsorption sites and functional groups. Between pH 5 and 9, the MNZ sorption was not
significantly affected. Kinetic studies revealed that the MNZ adsorption closely followed the
Avrami model, with no dominant process controlling the sorption rate. The study of the effects
of foreign ions revealed that the addition of carbonate raised the MNZ removal efficiency of
LECA by 8% and the total removal of MNZ by MgO/LECA. Furthermore, nitrate and
hardness only marginally influenced the MNZ removal efficiency and their effects can be
ranked in the order of carbonate>nitrate>hardness. The isotherm adsorption of MNZ was best
fitted with the Langmuir model enlighten the monolayer MNZ adsorption on the homogeneous
LECA and MgO/LECA surfaces. The maximum adsorption capacity under optimum
conditions was enhanced from 56.31 to 84.55 mg/g for LECA and MgO/LECA, respectively.
These findings demonstrated that the MgO/LECA nanocomposite showed potential as an
efficient adsorbent for MNZ removal.

https://www.sciencedirect.com/science/article/abs/pii/S0045653517302217

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