title: Use of cyclodextrin and calcium chloride for enhanced removal of mercury from soil.
abstract: The use of solutions containing carboxymethyl-beta-cyclodextrin (CMCD) or CaCl2 for enhancing the removal of Hg from a sandy soil was investigated using batch and column experiments. The retention of Hg appeared to be controlled by specific adsorption reactions, which greatly constrained Hg removal when using water (KNO3 solution) to flush columns packed with contaminated soil. The results showed that the two reagents did enhance the removal of Hg from the soil. For example, 81% and 60% of Hg was recovered after 50 pore volumes of flushing with 50 mM CaCl2 and 2 mM CMCD, respectively, compared to 24% recovery for a 10 mM KNO3 solution. However, significant tailing and delayed recovery of Hg during the elution process occurred in the presence of all reagents, indicating that the removal of Hg from the soil was rate limited.
authors.affiliation: Department of Soil, Water, and Environmental Science, The University of Arizona, Tucson, Arizona 85721, USA.
authors.forename: Xiaojiang
authors.initials: X
authors.lastname: Wang
authors.forename: Irfan
authors.initials: I
authors.lastname: Yolcubal
authors.forename: Weizi
authors.initials: W
authors.lastname: Wang
authors.forename: Janick
authors.initials: J
authors.lastname: Artiola
authors.forename: Raina
authors.initials: R
authors.lastname: Maier
authors.forename: Mark
authors.initials: M
authors.lastname: Brusseau
mesh_terms: D002122:Calcium Chloride / Q000737:chemistry*; D003505:Cyclodextrins / Q000737:chemistry*; D004787:Environmental Pollution / Q000517:prevention & control; D008628:Mercury / Q000737:chemistry* / Q000302:isolation & purification*; D012989:Soil Pollutants / Q000302:isolation & purification*; D012995:Solubility
chemical_list: D003505:Cyclodextrins; D012989:Soil Pollutants; D008628:Mercury; D002122:Calcium Chloride