| Summary: | This study explores the potential of turmeric powder and eggshell membrane as natural adsorbents
for the removal of Hg(II) in water. Turmeric powder was modified using carbon disulfide and
incorporated with silica gel via a sol-gel process to enhance its adsorption performance, yielding an
adsorbent called SiO2-MT. Whereas, the eggshell membrane (ESM) was used in its natural form due
to its intrinsic fibrous structure and functional groups. Adsorbents were characterized by FTIR, EDX,
FESEM, TGA, and BET, to assess their adsorption study, and the concentration of Hg(II) was
measured using cold vapor atomic absorption spectroscopy (CV-AAS). In the removal study of Hg(II)
in water, the effect of pH solution, adsorbent dosage, and contact time on adsorption efficiency was
studied, along with evaluations of isotherm and kinetic models. ESM showed superior adsorption
capacity (153.85 mg/g) compared to SiO2-MT (37.6 mg/g). Therefore, ESM was selected for further
study on the determination of Hg(II) using an innovative in-syringe membrane solid-phase extraction
(ISMSPE) technique, which offers significant advantages over traditional SPE methods. To enhance
the ISMSPE technique, parameters such as eluent type and concentration, adsorption-desorption
cycles, and eluent and sample volumes were optimized. This optimization resulted in a method with
a limit of detection (LOD) of 0.44 μg/L, a limit of quantification (LOQ) of 1.32 μg/L, and recovery
rates of 89.3–99.7%, with relative standard deviations (RSD) ranging from 1.0% - 8.0% for real water
samples. These results confirm the effectiveness of ESM as a sustainable, high-performance sorbent
for the removal and determination of Hg(II) in water, providing a greener and more effective approach
to water treatment and environmental monitoring.
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