Adsorption of Hg۲+ 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), ۷۷ 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-Na۲). Our novel material was then used in the batch adsorption of Hg۲+, where the maximum conditions were reached after ۳۵ minutes of contact time at pH ۳ with the adsorbent weight of ۰.۱ g. The maximum adsorption amount of Hg۲+ in the aqueous phase was ۱۳۹.۶۴ mg Hg۲+ / g (modified MCF). The maximum desorption ratio of Hg۲+ was ۷۵.۲۳% achieved by using ۰.۱ mol/L hydrochloric acid solution. The process for the adsorption of Hg۲+ conforms to the quasi-second-order adsorption kinetics and Langmuir adsorption isotherm. The results of the low-temperature N۲ adsorption-desorption curve at ۷۷ K showed that Hg۲ + had entered the MCF pore channels. This novel material is effective in removing Hg۲+ from the water medium via batch adsorption.

کلیدواژه ها:

Hg۲+ ، MCF ، Disodium ethylenediaminetetraacetate ، Adsorption ، Modification ، Quasi-second-order kinetics ، Adsorption kinetics ، Langmuir adsorption isotherm