Kinetic and Thermodynamic Study of Chromium Picolinate Removing from Aqueous Solution onto the Functionalized Multi-Walled Carbon Nano Tubes

Abstract

In the present research, the Functionalized Multi-Walled Carbon Nano Tubes (FMWCNTs) were functionalized and then were characterized by using the Fourier Transform infrared spectroscopy (FT-IR), X-Ray powder Diffraction (XRD), Scanning Electron Microscopy (SEM), Brunauer –Emmett-Teller and Barett-Joyner –Halenda (BET/BJH) and Particle Size Analyzer (PSA) techniques. Subsequently, the functionalized multi-walled carbon nanotubes were used to remove chromium picolinate (ChP) drug from the aqueous media, and its ability for ChP adsorption was also evaluated. To achieve this purpose, the effects of the various parameters such as pH, initial concentration of the sorbate, sorbent dosage, temperature, and contact time on the removal percentage of ChP drug onto the FMWCNTs adsorbent were studied and reported. Based on the experimental results, the optimum conditions to perform the adsorption experiments were determined. In addition, the experimental results were examined using some suitable isotherm models, and it was found that the Langmuir isotherm model is more suitable for fitting the results of the considered adsorption process. Finally, the kinetic and thermodynamic behavior of the ChP adsorption onto the FMWCNTs sorbent were considered and the related results indicated that the studied adsorption process is exothermic and exergonic and almost is physical adsorption. In addition, the kinetic results showed that the adsorption of ChP onto the FMWCNTs adsorbent obeys the pseudo-first-order reaction law from the kinetic point of view.