Evaluation of the Mn(II) adsorption potential of SiO2 obtained by different wet chemical methods

This paper describes the development of SiO2 by 2 different wet chemical methods: polymeric precursor (PP) and sol‐gel (SG). These samples were used as adsorbents of Mn(II) metal ions. Physicochemical characteristics of the 2 adsorbents were established, while zeta potential, Scanning Electron Microscopy, and Brunauer‐Emmett‐Teller (BET) surface area methods were further employed for characterization. Efficiencies of the prepared adsorbents in the adsorption of Mn(II) from aqueous solutions were investigated. The BET surface areas of the prepared adsorbent were 171 and 7 m2 g−1 for SiO2 PP and SiO2 SG, respectively. Optimal adsorption occurred at pH 8.5, 5g L−1 of adsorbent concentration, and 90 minutes of contact time for both adsorbents. The Langmuir and Freundlich isotherms models fitted the experimental data of SiO2 PP and SiO2 SG, respectively, and SiO2 PP showed the highest adsorption capacity due, probably, to its greater specific area.