Exploring nickel-modified sodalite zeolite for efficient methyl orange removal from aqueous solutions: A comprehensive mechanistic and equilibrium analysis

초록

In this work, a sodalite zeolite was synthesized and subsequently impregnated with nickel solution to produce Ni-Sodalite zeolite (Ni/Sodalite). The structural and morphological characteristics of both the unmodified and Ni-modified sodalite were investigated using X-ray diffraction (XRD), Fourier Transform Infrared (FT-IR) spectroscopy, and Scanning Electron Microscopy coupled with Energy Dispersive Spectrometer (SEM/EDX). Compared to the unmodified sodalite, the Ni/Sodalite exhibited a significantly enhanced affinity for Methyl Orange (MO) dye, attaining maximum adsorption capacities of 18.37 and 43.78 mg/g at 50 °C. Equilibrium data were well-described by the non-linear Freundlich isotherm model, suggesting that the adsorption of MO occurs over heterogeneous sites on both sodalite and Ni-modified sodalite surfaces. Additionally, the adsorption kinetics were found to conform to a pseudo-second-order model. Thermodynamic parameters (∆G, ∆H, and ∆S) computed at various temperatures indicated that the MO adsorption process was spontaneous and endothermic, and was accompanied by reduced randomness of the dye molecules on the adsorbent surface.

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