title: Mercury(II) exchange by highly charged swelling micas, sodium Engelhard titanosilicate-4, and sodium titanosilicate.
abstract: Selective Hg(2+)-exchange properties of highly charged sodium swelling micas (Na-2-, Na-3-, and Na-4-micas), sodium Engelhard titanosilicate-4 (Na-ETS-4), and sodium titanosilicate were determined by use of distribution coefficients (K(d)), ion-exchange isotherms, and Kielland plots for their potential use of Hg decontamination from groundwater and soils. X-ray diffraction (XRD) patterns after 2Na(+) → Hg(2+) exchange were collected to check for change in (001) spacings of differently charged sodium micas. The isotherms and Kielland plots suggested that Na-ETS-4 was highly selective for Hg(2+). Also, the K(d) value of Na-ETS-4 was the highest among the tested exchangers, supporting its high selectivity. Hg releases from Hg-exchanged Na-4-mica and Na-ETS-4 were found to be lower compared to other samples tested with simulated groundwater. The (001) spacings of sodium micas after Hg(2+) exchange changed from ∼ 12 to ∼ 14 Å or/and 12 Å depending on their layer charge density and the uptake amount of Hg. Our results suggest that Na-ETS-4 is a good candidate for mercury(II) decontamination from groundwater and soils.
authors: Department of Crop and Soil Sciences and Materials Research Institute, The Pennsylvania State University, University Park, Pennsylvania 16802, USA.
authors: Young Dong
authors: YD
authors: Noh
authors: Sridhar
authors: S
authors: Komarneni
mesh_terms: D000538:Aluminum Silicates / Q000737:chemistry*; D060587:Groundwater; D006863:Hydrogen-Ion Concentration; D007474:Ion Exchange; D007700:Kinetics; D008628:Mercury / Q000737:chemistry*; D017640:Silicates / Q000737:chemistry*; D013696:Temperature; D014025:Titanium / Q000737:chemistry*; D014961:X-Ray Diffraction
chemical_list: D000538:Aluminum Silicates; D017640:Silicates; D014025:Titanium; D008628:Mercury; C011934:mica