Adsorption studies of arsenic on nano aluminium doped manganese copper ferrite polymer (MA, VA, AA) composite: Kinetics and mechanism

Aluminium doped nano manganese copper ferrite (average size of 13 nm) was synthesized by the chemical co-precipitation method and nanocomposite was prepared by doping this ferrite in methacrylate, vinyl acetate and acrylic acid polymer through slow heating process. This nanocomposite was used as an adsorbent for the removal of arsenic from aqueous solution. The equilibrium data was fitted to Freundlich, Langmuir, Dubinin Rudushkevish and Flory Huggins models. The maximum adsorption capacity (qm) of arsenic on the nanocomposite was found to be 0.053 mg g−1 which is higher than that of many other adsorbents reported in literature. Mean sorption energy obtained from DR isotherm was 40.98 kJ mol−1 indicating chemical nature of the adsorbate–adsorbent interactions. The pseudo-second order kinetic model gave a better fit to the experimental data indicating involvement of both the external as well as internal mass transfer. Bangham's model and intraparticle diffusion model were applied to investigate mechanism of the adsorption process. Non linear Bangham plot and significant value of intercept obtained from intraparticle diffusion model showed the film diffusion as well as pore diffusion to be the rate limiting steps.

Plot of pseudo-second order kinetic model for the adsorption of arsenic (100 ppb) on the nanocomposite at 313 K. The adsorption process follows the pseudo-second order kinetic.Figure optionsDownload as PowerPoint slideHighlights
• A novel adsorbent has been prepared for the removal of arsenic from aqueous solution.
• The nanocomposite adsorbent shows better adsorption capacity as compared to other adsorbents reported in literature.
• The adsorption process follows the pseudo-second order kinetic model.
• The adsorption process shows the chemisorption.