Adsorption of Hg2+ onto Novel Mesocellular Foams Silica Functionalized with Disodium Ethylenediaminetetraacetate: Thermodynamics, Isotherm, and Kinetics Studies

Mercury is one of the most important heavy metal elements of environmental pollution, and it is very important for its control. MesocCllular Foam (MCF) silica was prepared by hydrothermal method, and the prepared material was characterized by Powder X-Ray Diffraction (XRD), Scanning Electron Microscopy (SEM), 77 K low-temperature nitrogen gas adsorption-desorption. Herein, the authors aimed to improve the adsorptive performance of MCF against mercury ions through a functionalization using disodium ethylenediaminetetraacetate (EDTA-Na2). Our novel material was then used in the batch adsorption of Hg2+, where the maximum conditions were reached after 35 minutes of contact time at pH 3 with the adsorbent weight of 0.1 g. The maximum adsorption amount of Hg2+ in the aqueous phase was 139.64 mg Hg2+ / g (modified MCF). The maximum desorption ratio of Hg2+ was 75.23% achieved by using 0.1 mol/L hydrochloric acid solution. The process for the adsorption of Hg2+ conforms to the quasi-second-order adsorption kinetics and Langmuir adsorption isotherm. The results of the low-temperature N2 adsorption-desorption curve at 77 K showed that Hg2 + had entered the MCF pore channels. This novel material is effective in removing Hg2+ from the water medium via batch adsorption.