Fabrication of Cu-Al2O3/ceramic particles by using brick particles as supports for highly-efficient selenium adsorption

Abstract

Selenium in organism and drinking water resembles a two-edged sword due to the effective prevention of Keshan disease at appropriate selenium concentrations and adverse impacts on human health at high selenium concentrations. Herein, an attempt was made to separate selenium from aqueous solution by Cu-Al2O3/ceramic particles. The Cu-Al2O3/ceramic particles with high BET surface areas were prepared by two-step deposition of metal oxides and H2 reduction using brick particles as supports and evaluated for their selenium separation. SEM and BET analysis revealed that the ceramic particles have rough surfaces with many micro- or nanoprotrusions constituted by Al2O3 particles and copper nanoparticles, and high BET surface areas up to ~125.87 m2/g and hierarchical porosity. Batch selenium adsorption test was conducted to investigate the selenium separation process via various experimental conditions such as pH values, adsorbent dosage, initial selenium concentration and contact time. Adsorption results show that the selenium equilibrium adsorption onto Cu-Al2O3/ceramic particles can be reached within 60 min with the maximum selenium adsorption efficiency of 95.36%. Selenium adsorption onto Cu-Al2O3/ceramic particles was found to be pH dependent and the appropriate selenium adsorption capacity is nearly constant in the pH range 2–8. In addition, the influence of addition of the co-existing ions on the selenium adsorption was also studied and CO32- anions was found to have negligible impact on selenium adsorption process. Combining high selenium adsorption capacity, rapid adsorption kinetics, and suitable adsorption pH, Cu-Al2O3/ceramic particles have potential applications adsorption. This study provides a waste-to-resource strategy to fabricate functional materials that can be employed as a reliable adsorbent for separation and adsorption of rare elements.