Removal of EBT dye from aqueous solution by modified MoNiO4 adsorbent
Farhad Salimi, Vahid Valiei, Changiz Karami
Abstract
ABSTRACT In this study, the perovskite structures of MoNiO 4 (MNO) and modified MoNiO 4 (MMNO) nanoparticles were synthesized and used to remove a textile dye, Eriochrome Black T (EBT), from water solution. The MMNO structure was synthesized using the citrate sol–gel method. The Fourier-transform infrared spectroscopy, scanning electronic microscopy analysis, pore size distribution analysis, the N 2 adsorption (Brunauer–Emmett–Teller (BET) specific surface area) analysis, and X-ray diffraction spectroscopy were used to characterize the prepared nanoparticles. The BET results showed that the surface area for MMNO nanoparticle increased slightly with the citrate sol–gel method. The effect of operating parameters such as adsorbent dosage, pH, and contact time were investigated. The maximum adsorption of EBT was obtained as 6.66 and 68.03 mg/g for MNO and MMNO, respectively. The optimum conditions were pH of 7, mixing time of 25 min, the temperature of 25°C, and 5 g/L MNO and MMNO for 100 mg/L EBT solution. The adsorption isotherm and the kinetic study showed that the adsorption EBT on adsorbents (i.e., MNO and MMNO) obeyed Langmuir isotherm and pseudo-second-order model, respectively. Moreover, measuring the thermodynamic parameters revealed that the adsorption process was non-spontaneous and endothermic.