▎ 摘　　要

Heavy metals are present in sewage in several forms, increasing treatment problems and causing major environmental problems. Highly selective adsorption of the most dangerous heavy metals is one of the most important methods for water treatment and resource utilization. In this regard, a new mercapto grafted magnetic graphene oxide nanoadsorbent (MGO-SH) was synthesized and applied to remove excess mercury from aqueous solutions. To synthesize MGO-SH, GO was reacted with thionyl chloride (SOCl2) and the acylated GO (GO-COCl) was grafted with p-Mercaptoaniline (MA). To characterize the synthesized nanoparticles, Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), and scanning electron microscope (SEM) were used. Some of the key parameters that might affect the removal efficacy, such as pH, nanoadsorbent amount, contact time, and some co-existing cations found in aqueous solutions, were also investigated. The optimum conditions to be as follows: adsorbent dosage 20 mg, pH of solution 6, and contact time of 20 min. The results showed that the equilibrium data for mercury sorption onto the proposed nanoadsorbent abide the Freundlich equation. Moreover, thermodynamic studies indicated that the adsorption is spontaneous and endothermic. Finally, the proposed nanoadsorbent was successfully used to remove mercury from the real water samples. Therefore, these nanosorbents could be good candidates for Hg (II) removal with the advantages of high sensitivity, high capacity, cost-effectiveness and ease of use.