synergistic adsorption of methyl orange using mgo/clinoptilolite nanocomposites: characterization, isotherm analysis, and optimization through response surface methodology

A novel adsorbent combining magnesium oxide (mgo) nanostructures with natural clinoptilolite (cp) zeolite, a cost-effective clay, was developed. this adsorbent aimed to stabilize mgo nanostructures and explore the synergistic effect of the zeolite surface and mgo groups in adsorbing methyl orange (mo), a toxic anionic dye. various adsorbents were synthesized via a co-precipitation method and characterized using x-ray diffraction (xrd), scanning electron microscopy (sem), brunauer-emmett-teller (bet) surface area analysis, and fourier transform infrared (ft-ir) spectroscopy. the findings revealed that the adsorbent with 20 wt.% mgo/cp exhibited superior performance in mo adsorption. isotherm data were evaluated using multiple models, including langmuir, freundlich, sipes, temkin, flory-huggins, and redlich–peterson. for the 20 wt.% mgo/cp adsorbent, the temkin and langmuir isotherms were deemed most fitting for equilibrium analysis. kinetic studies favored the fractal-langmuir model, and thorough thermodynamic investigations were conducted. response surface methodology (rsm) was utilized to optimize the effects of ph, temperature, and adsorbent-to-adsorbate ratio (a/a) on dye removal efficiency. the optimal conditions for maximal dye removal were identified at ph 4.9, a temperature of 54.5 °c, and an a/a ratio of 0.129 g/g. under these conditions, the experimental removal of mo was 98.5%, closely aligning with the predicted value of 99.95%.