Effect of turbulent stirring and orbitally shaking on methylene blue adsorption by (NH₄)₂V₆O₁₆·1.5H₂O nanostructures: An intra-diffusion model analysis

Due to the importance and advancements of the dye adsorption capacity for waste water treatments, it becomes really important to understand the efficient adsorption process and mechanism. In this study, (NH₄)₂V₆O₁₆.1.5H₂O consisting of porous 3D nest-like nanostructures were prepared using the sol-gel method for the removal of methylene blue dye from contaminated wastewater. The prepared material was systematically characterized to determine its structural and morphological properties using various techniques, including X-ray diffraction, field emission scanning electron microscopy, and high resolution transmission electron microscopy. The impact of various agitation techniques on the dye adsorbent material was analyzed using different mixing techniques such as turbulent stirring and orbitally shaking. These mechanical processes enhance the interaction between dye molecules and adsorbent nanostructures by promoting mass transfer and increasing the collision frequency. The kinetic models of dye adsorption on the (NH₄)₂V₆O₁₆.1.5H₂O nanostructures were conducted to investigate the dye adsorption mechanism. In the intraparticle diffusion model, the rate constant (k_d) offers insights into the diffusion rate within the adsorbent nanostructures. The higher value of k_d for turbulent stirring in comparison to orbital shaking can be dedicated to the creation of more active adsorption sites by disruption of consecutive liquid layers by stirring.