Abstract—Hg (II) is one of the most toxic elements in the aquatic environment and its immobilization as water insoluble form of Hg (0) is the aim of this research. Dilute sulfuric and phosphoric acids were used to prepare sulfuric acid dehydrated carbon (SDC) and phosphoric acid dehydrated carbon (PDC), respectively from peanut shell at 170 oC. Removal of Hg (II) from aqueous nitrate solution was tested at different initial pH, contact time, concentration and temperature. Maximum sorption took place at initial pH 2 and equilibrium obtained within ~ 70 hr on both carbons with increased uptake as temperature rises. Activation energy, Ea, was >40 kJ/mol indicating chemical adsorption. Hg (II) uptake was found to follow well the Langmuir adsorption model with higher uptake for SDC than PDC. Temperature rise led to increased removal of Hg (II) on both carbons. Scanning electron microscopy (SEM) showed micro-droplets of Hg (0) on the carbon surface that was confirmed using energy dispersive spectroscopy (EDS). Hg (II) reduction was accompanied by surface oxidation. Hg (0) was collected from mercury loaded carbons via sonication under water. Dehydrated carbons shows promising results for Hg (II) immobilization as Hg (0).

Index Terms—dehydrated, carbon, Hg (II), reduction, sulfuric, phosphoric


Cite: El-Said I. El-Shafey, "Immobilization of Hg (II) to Hg (0) on Reducing Dehydrated Carbons," Journal of Medical and Bioengineering, Vol. 3, No. 4, pp. 292-296, December 2014. Doi: 10.12720/jomb.3.4.292-296