title: Effects of metal-soil contact time on the extraction of mercury from soils.
abstract: To investigate the mercury aging process in soils, soil samples were spiked with inorganic mercury (Hg(II)) or methylated mercury (MeHg) and incubated for 2, 7, 14 or 28 days in the laboratory. Potential availability of mercury, assessed by bovine serum albumin (BSA) or calcium chloride (CaCl2) extraction, decreased by 2-19 times for Hg(II) or 2-6 times for MeHg, when the contact time increased from 2 to 28 days. Decreased Hg(II) extraction could be explained by Hg(II) geochemical fractionation, i.e., Hg(II) migrated from more mobile fractions (water soluble and stomach acid soluble fractions) to refractory ones (organo-complexed, strongly complexed and residual fractions) over time, resulting in more stable association of Hg(II) with soils. In addition, decrease of mercury extraction was more evident in soils with lower organic content in most treatments, suggesting that organic matter may potentially play an important role in mercury aging process. In view of the significant decreased Hg(II) or MeHg extraction with prolonged contact time, mercury aging process should be taken into account when assessing risk of mercury in contaminated soils.
authors.affiliation: State Key Laboratory of Pollution Control and Resource Reuse, School of Environment, Nanjing University, Nanjing, Jiangsu, People's Republic of China.
authors.forename: Lan
authors.initials: L
authors.lastname: Ma
authors.forename: Huan
authors.initials: H
authors.lastname: Zhong
authors.forename: Yong-Gui
authors.initials: YG
authors.lastname: Wu
mesh_terms: D001682:Biological Availability; D002122:Calcium Chloride; D005591:Chemical Fractionation; D002681:China; D008628:Mercury / Q000032:analysis / Q000302:isolation & purification* / Q000493:pharmacokinetics; D012710:Serum Albumin, Bovine; D012987:Soil / Q000737:chemistry*; D012989:Soil Pollutants / Q000032:analysis / Q000302:isolation & purification* / Q000493:pharmacokinetics; D013997:Time Factors
chemical_list: D012987:Soil; D012989:Soil Pollutants; D012710:Serum Albumin, Bovine; D008628:Mercury; D002122:Calcium Chloride