123rd General Meeting of the KCS

Type Oral Presentation
Area Student Oral Presentation
Room No. Room 203
Time THU 09:15-09:30
Code ENVR.O-2
Subject Removal of aqueous Hg(II) using indium-modified bimetallic iron particles
Authors Qasim Ghulam Hussain, Seunghee Han1,*
Department of Environmental Engineering, Gwangju Institute of Science and Technology, Korea
1School of Environmental Sciences and Engineering, Gwangju Institute of Science and Technology, Korea
Abstract Zero-valent iron (ZVI) one of the most capable remediation technologies for organic and inorganic pollutants in water associated with its low cost and high reactivity. In order to maximize the reactivity and durability of microscale ZVI, the surface of ZVI was impregnated with Ni, Cu, and In, and the removal efficiency was batch-tested for 60 minutes with 250 nM of aqueous Hg(II) under pH 7. Among these metals, In-doped ZVI (In-ZVI) showed the highest Hg(II) removal efficiency of 99% along with the highest concentration of Hg(0) in the headspace, while the Hg(II) removal efficiency ranged from 3 to 15% with Ni and Cu modification. The sorption of Hg was better explained by Freundlich model than Langmuir model, suggesting that it may take palace in a multilayer adsorption manner with irregular energy distributions. Furthermore, there was no significant decrease in the Hg(II) removal efficiency after seven successive runs, while it was largely decreased at the forth cycle without In doping. The various control test results demonstrated that simple Hg sorption on ferric oxides or Hg reduction by In(0) or Fe(II) on ferric layer cannot support high removal efficiency of In-ZVI particles. Overall results suggest that a galvanic cell formed between In(0) oxidation and Fe(III) reduction on the surface of ZVI leads to the generation of atomic hydrogen, and it highly increased the Hg(II) reduction rate due to enhanced electronic interactions between Fe, In, and Hg.
E-mail qasimgh@gist.ac.kr