Eriochrome Black T removal from water solution by modified LaNiO3: kinetic, isotherm, and thermodynamic studies

Abstract

In this study, LaNiO3 (LNO) and modified LaNiO3 (MLNO) nanoparticles with perovskite structures were synthesized using the citrate sol-gel method and used for removal of the Eriochrome Black T (EBT) dye from water. The increase of the surface area on the LNO was created by enhancing the holes on its surface. The transmission electron microscopy, scanning electronic microscopy, the N-2 adsorption (Brunauer-Emmett-Teller specific surface area) and pore size distribution analysis and X-ray diffraction spectroscopy were used to characterize the prepared nanoparticles. The results of the surface area analysis indicated that the number of MLNO samples increased through the method applied in this paper. The effects of adsorbent dosage, pH, and contact time were investigated and 25.90 and 19.27 mg/g of LNO and MLNO were respectively obtained for the adsorption of the maximum EBT. The optimum conditions for 100 mg/L EBT solution were pH of 5 and 0.3 g/L LNO and MLNO. Freundlich isotherm and pseudo-second-order model better predicted the adsorption isotherm and adsorption kinetics, respectively. Moreover, thermodynamic parameters have been measured and results indicate that the adsorption process was spontaneous and exothermic for LNO and spontaneous and endothermic for MLNO.