Synthesis Of CuO-Al₂O₃ Using Natural Plant As Templates And Their Adsorption Properties

Because of its large specific surface area and pore structure, porous nanometer metal oxide has been widely used in dye wastewater treatment. Methyl blue(MB) dye is a kind of typical acidic cationic dyes in dye wastewater, with its solution as the simulated dye wastewater has practical significance. Therefore, this work was focused on synthesis of different biomorphic nanoscale copper aluminum composite oxide as adsorbent to remove MB in dye wastewater.In the present work, different kinds of cotton, Boston ivy stem and bamboo pole employed as the templates for the synthesis of cotton template biomorphic Cu O-Al2O3,Boston ivy stem template biomorphic Cu O-Al2O3 and bamboo pole template biomorphic Cu O-Al2O3. A series of methods of XRD, TEM, FESEM, FTIR, N2 adsorption-desorption,TG-DTA and UV-vis were employed for the study and characterization of the components,morphologies, microstructures and adsorption properties.The optimization of synthesis of Cu O-Al2O3 has been done by varying ratios of Cu to Al and calcination temperature. The removal of MB on conditioned Cu O-Al2O3 adsorbent was also investigated in batch adsorption studied, where the impact of the amount of adsorbent, the p H of solution, initial concentration, adsorption time and temperature were evaluated. Experimental results indicated that the adsorption capacity was enhanced with an increase in initial concentration and temperature. The high percentage removal of MB could be retained over a relatively wide p H range. Equilibrium adsorption data were analyzed using Langmuir, Freundlich and Dubinin-Radushkevich isotherm models, results showed that the adsorption isotherms of cotton template biomorphic Cu O-Al2O3 and Boston ivy template biomorphic Cu O-Al2O3 were found to be well described by Freundlich model and the adsorption isotherms of bamboo template biomorphic Cu O-Al2O3 were well fitted with Langmuir model. The pseudo-first-order,pseudo-second-order and intraparticle diffusion models were applied to test the kinetic data, it was inferred that the pseudo-second-order kinetic model agrees very well with the dynamical behaviour for the adsorption.