Abstract
Heavy metals, such as vanadium, are some of the most toxic types of water contaminants. In this study, vanadium was removed using a new nanocomposite adsorbent called PdO-MWCNTs. The effects of pH and initial concentration of vanadium (V) on the removal efficiency of this metal by using PdO-MWCNTs were investigated in the first step of the study. Vanadium removal decreased as pH increased to 3–10. The removal efficiency then decreased. Response surface methodology and central composite design were applied to investigate experimental data. Initial concentration of V (mg/L), pH, and dosage of adsorbent (g/L) were the independent factors. Based on RSM, the removal effectiveness of vanadium was 95.47% at the optimum of initial concentration (60.0mg/L), pH (3.0), and adsorbent dosage (1.0g/L). Adsorption isotherm study shows the Langmuir isotherm could explain vanadium adsorption by PdO-MWCNTs better than the Freundlich isotherm. The adsorption equilibrium and kinetic data were well fitted and found to be in good agreement with the Langmuir isotherm and pseudo-second-order kinetic model.
3-D surface plot for the combined effect of pH (A), initial concentration of V5+ (B) and adsorbent dosage (C) on V5+ removal. [Display omitted]
•The PdO-MWCNTs show considerable advantages on the removal yield of V5+.•Response surface methodology to analyze the data.•Box–Behnken Design was employed to optimize linezolid antibiotic adsorption process.•Interactive effects of adsorption parameters on V5+ adsorption capacity were investigated.