Chemical Forms of as Aged in a Former Smelter Site in Relation to in vitro Bioaccessibility
作者单位：Department of Civil and Environmental EngineeringSeoul National UniversitySeoulKorea School of Earth and Environmental SciencesSeoul National UniversitySeoulKorea
会议名称：《2012年环境污染与大众健康学术会议》
会议日期：2012年
学科分类：083001[工学-环境科学] 0830[工学-环境科学与工程（可授工学、理学、农学学位）] 08[工学]
基 金：supported by the Korea Ministry of Environment as the GAIA (Geo-Advanced InnovativeAction) Project
关 键 词：in vitro bioaccessibility test sequential extraction chemical form arsenic refractory organic matter
摘 要：This study characterizes the total As concentration and the As bioaccessibility with the 5-step sequential extraction and the in vitro bioaccessibility test using three soil samples from a former smelter site, and discusses the chemical speciation obtained by the sequential extraction and the soil properties that influence the bioaccessibility. Results from the 5-step sequential extraction showed that 99.2, 94.8, 96.2% of the total As concentration in the soil A, B, and C, respectively, hosted in the residual form （i.e., fraction 5）. Interestingly, some portion of the As in the fraction 5 was not expected to contribute to bioavailability nor to be bioacceessible. The bioaccessible As in the soil B （11.9%） was higher than that in the soil A （0.64%） and the soil B （2.02%）. The in vitro bioaccessibility test was conducted aging with the residual form using the organic matter-specific （i.e., HClO 4 ） and the mineral-specific extractant （i.e., HF） to determine the bioaccessibil- ity of the residual form. The results showed that the As associated with organic matter was more bioaccessible than the As associated with silicate minerals. In addition, the residual form with higher humic and fulvic acids contents showed greater bioaccessibility of the refractory organic matter in soil. This study indicates that the composition of the residual organic matter may be important when estimating the bioaccessibility of As.