Response Surface Optimization of Removal of Rhodamine B Dye Using a Synthesized Ni-Based Metal-Organic Framework Adsorbent

In this research, removal of Rhodamine B (RB) dye from aqueous samples was investigated by a new Ni (II) based metal-organic framework (MOF) synthesized named [Ni(II) L]n [where L= 4, 4′-diamino diphenyl sulfone] (Ni- MOF). These materials were fully characterized using Fourier transform infrared (FT-IR), field emission scanning electron microscopy (FESEM), energy-dispersive X-ray spectroscopy (EDX), TGA/DTG and X-ray diffraction (XRD). WE used response surface methodology (RSM) based on the central composite design (CCD) to study the effects of four various parameters including dye concentration, MOF dosage, contact time and pH on the process of adsorption. The optimal condition for removal of RB was achieved for pH=9, 0.063 g of MOF for 25 mL of 16.06 mg/lit dye concentration and contact time of 39 minutes. Adsorption equilibrium and kinetic data were fitted with the Langmuir monolayerisotherm model (qmax=163.66 mg/g and R2= 0.9827) and like pseudo second-order kinetics mechanism (R2=0.992).  isotherm model (qmax=163.66 mg/g and R2= 0.9827) and like pseudo second-order kinetics mechanism (R2=0.992).