Modeling and experimental study of vanadium adsorption by iron-nanoparticle-impregnated activated carbon

Research on Chemical Intermediates - Iron-nanoparticle-impregnated activated carbon (IrAC) nanocomposite was synthesized as a new vanadium adsorbent. The vanadium adsorption rate for commercial...     

Vanadium separation with activated carbon and iron/activated carbon nanocomposites in fixed bed column: experimental and modelling study

In this work, iron nanoparticles were impregnated onto a commercial activated carbon surface to produce a novel adsorbent called iron-activated carbon nanocomposite (I-AC). Commercial activated carbon (CAC) and I-AC were used for vanadium separation in a fixed-bed column. The effects of various operating parameters such as inlet vanadium ion concentration, adsorbent dose and volumetric flow rate on vanadium separation performance of CAC were investigated. The performance of both adsorbents was compared in three adsorption/desorption cycles. The experimental breakthrough curves of vanadium ions in the fixed-bed column were modeled using the film-pore-surface diffusion model (FPSDM). The four mass transfer parameters characterizing this model, namely the external mass-transfer coefficient (k _f ), pore and surface diffusion coefficients (D _p and D _s ), and axial dispersion coefficient (D _L ) were evaluated through the model. Modelling and experimental results showed that the I-AC nanocomposite has a better performance for vanadium separation in comparison to AC. Sensitivity analysis on the FPSDM showed that the pore and surface diffusion, external mass transfer and axial dispersion play a significant role in vanadium separation using the I-AC. On the other hand, surface diffusion resulted to be relatively less important when CAC was used.     

Chemical modification of activated carbon surface with iron functional groups for efficient separation of vanadium: batch and column study

In this study, iron functional groups-impregnated activated carbon (IIAC) composite was prepared as a novel adsorbent for vanadium separation. Adsorption experiments were performed in batch and column systems, and the effects of various operating parameters, such as solution pH, initial concentration, contact time, and temperature, were evaluated. The kinetic data confirmed the validity of the pseudo-second-order kinetic model for vanadium adsorption on IIAC. The sorption equilibrium data were analyzed using Langmuir, Freundlich, and Dubinin–Radushkevich isotherm models. The results showed that IIAC has a vanadium ions adsorption capacity of 313 mg g^?1. The activation and thermodynamic parameters were determined using kinetics and equilibrium data. The experimental data of the column adsorption process were fitted by Thomas and BDST models. The results showed that Thomas model can well describe the breakthrough curves. The column experiments showed that IIAC composite has good adsorption performance for vanadium ions adsorption.