A novel adsorbent, based on modifying graphene oxide (GO) chemically with 2-pyridinecarboxaldehyde
thiosemicarbazone (2-PTSC) as ligand, was designed by facile process for removal of Hg(II) from aqueous
solution. Characterization of the adsorbent was performed using various techniques, such as FT-IR, XRD,
XPS, SEM and AFM analysis. The adsorption capacity was affected by variables such as adsorbent dosage,
pH solution, Hg2+ initial concentration and sonicating time. These variables were optimized by rotatable
central composite design (CCD) under response surface methodology (RSM). The predictive model for Hg
(II) adsorption was constructed and applied to find the best conditions at which the responses were maximized.
In this conditions, the adsorption capacity of this adsorbent for Hg2+ ions was calculated to be
309 mg g1 that was higher than that of GO. Appling the ultrasound power combined with adsorption
method was very efficient in shortening the removal time of Hg2+ ions by enhancing the dispersion of
adsorbent and metal ions in solution and effective interactions among them. The adsorption process
was well described by second-order kinetic and Langmuir isotherm model in which the maximum
adsorption capacity (Qm) was found to be 555 mg g1 for adsorption of Hg2+ ions over the obtained adsorbent.
The performance of adsorbent was examined on the real wastewaters and confirmed the applicability
of adsorbent for practical applications.