A magnetic nanoadsorbent based on expanded graphite with enhanced surface area for the removal of sulfamethoxazole and malachite green from aqueous solutions

In this study, a new magnetic nanoadsorbent (denoted as Fe۳O۴/EXG/Cellulose) was synthesized using expanded graphite (EXG), microcrystalline cellulose and Fe۳O۴ nanoparticles. The Fe۳O۴/EXG/Cellulose was used as an effective nanoadsorbent for the removal of sulfamethoxazole (SMX) and malachite green (MG) from aqueous solutions using batch process. The Fe۳O۴/EXG/Cellulose was fully characterized by the Fourier transform infrared (FT-IR), X-ray diffraction (XRD), Energy-dispersive X-ray spectroscopy (EDX), Brunauer-Emmett-Teller (BET), Field emission scanning electron microscopy (FESEM), and transmission electron microscopy (TEM) analyses. Based on the BET analysis, an improved surface area from ۱۰.۳۲ to ۷۱.۸۶ m۲ g–۱ was achieved after the modification of expanded graphite using microcrystalline cellulose. The adsorption capacities for the MG dye and SMX drug were determined to be ۱۰۹.۹ and ۳.۹ mg/g, respectively. In addition, the adsorption process of SMX and MG by the Fe۳O۴/EXG/Cellulose was studied with isotherm and kinetic models. The results indicate the adsorption of SMX and MG by nanocomposite better described with pseudo-second-order kinetic. In addition, Langmuir and Freundlich isotherm models well describe the adsorption of MG and SMX using Fe۳O۴/EXG/Cellulose, respectively. Furthermore, Fe۳O۴/EXG/Cellulose can be easily recycled and reused for over ۵ times and keeps a high level of adsorption efficiency.

کلیدواژه ها:

Nanoadsorbent ، Expanded graphite ، microcrystalline cellulose ، Sulfamethoxazole ، Malachite green