Highly efficient simultaneous adsorption of Cd(II), Hg(II) and As(III) ions from aqueous solutions by modification of graphene oxide with 3-aminopyrazole: central composite design optimization

摘要: In this work, graphene oxide (GO) chemically modified with 3-aminopyrazole (GO-f) was synthesized for the simultaneous adsorption of three heavy metals, Cd(II), Hg(II), and As(III), from aqueous solutions. The functionalized GO adsorbent acts as a good host welcoming incoming guest abundant nitrogen-containing functional groups on surfaces play an important role in metal adsorption. characterized by FT-IR, EDX, SEM TGA measurements. order to study influence pH, dose, initial ion concentration process, central composite design (CCD) employed. quadratic model used analysis variance indicated that ions strongly depends pH. Time-dependent can be demonstrated pseudo-second-order kinetic model, process modeled Langmuir isotherm adsorbent. Owing large specific surface area, hydrophilic behavior, moieties, showed excellent removal ability maximum capacity 285.714, 227.273, 131.579 mg g−1 cadmium, mercury arsenic ions, respectively. Thermodynamic revealed Hg(II) As(III) spontaneous endothermic. Moreover, competitive capacities were lower than noncompetitive ones. Also, same affinity observed adsorption: Cd(II) > As(III). A desorption favorable regeneration powder, even after adsorption–desorption cycles.