Adsorption of 4-Chloro-2-Nitrophenol by Zero Valent Iron Nanoparticlesand Pd-Doped Zero Valent Iron Nanoparticles Surfaces: Isotherm, Kineticand Mechanism Modeling

摘要

The removal of 4-Chloro-2-nitrophenol (4C2NP) from aqueous solutions using zero valent iron nanoparticles (nZVI) and Pd-doped zero valent iron nanoparticles (Pd-nZVI) was investigated in terms of initial pH, adsorbent dosage, contact time and temperature. The maximum adsorption occurred at the pH value of 5. The adsorbent studied exhibits high efficiency for 4C2NP adsorption and the equilibrium states could be achieved in 10 min in both the adsorbents. Equilibrium data were analyzed by two isotherms, namely the Freundlich isotherm and the Langmuir isotherm. The best fit to the data was obtained with the Langmuir isotherm. Adsorption kinetics data were modeled using the first order, the pseudo-first and pseudo-second order and Elovich equations. Results show that the pseudo-second order kinetics model was found to correlate the experimental data well.