123rd General Meeting of the KCS

Type Poster Presentation
Area Environmental Energy
Room No. Exhibition Hall 2
Time 4월 18일 (목요일) 11:00~12:30
Code ENVR.P-506
Subject Predicting mercury bioavailability in artificial and natural soils for earthworm Eisenia fetida using the diffusive gradients in thin films
Authors Viet Huu Nguyen, Seunghee Han*
School of Earth Sciences and Environmental Engineering, Gwangju Institute of Science and Technology, Korea
Abstract The diffusive gradients in thin films (DGT) probe is an effective tool for evaluating metal bioavailability, however, its applicability is subject to the type of metal and organism involved. In this study, the accumulated mass of Hg in DGT probes and in the earthworm species Eisenia fetida was monitored in artificial soils and natural river soils together with soil properties, to test if DGT technique can be used as a predicting method for the bioavailability of Hg to earthworms. In the Hg exposure tests using artificial soils prepared with different peat moss concentrations of 5, 10, 15, and 20% and varying pH values of 4.6, 5.6, and 6.2, the DGT-soil accumulation factor (DSAF) and biota-soil accumulation factor (BSAF) both increased as the peat moss content decreased and the pH increased. Across diverse soil properties, steady-state Hg in earthworm tissue showed a strong positive correlation with the DGT-measured Hg flux, while meager correlations were found between Hg concentration in earthworms and that in pore water (and acid-extractable), indicating that DGT-measured Hg flux is a better tool than conventional methods for predicting Hg bioavailability by earthworms inhabiting diverse types of soil. To test if DGT probes can be applicable for Hg bioavailability prediction in natural soils, DGT and earthworms were deployed in eight surface soils collected from Hyeoungsan (HS) River, along with the measurements of conventional soil properties (e.g., oxidation-reduction potential, pH, labile Hg, water holding capacity and organic matter content). The results revealed that the BSAF of Hg was able to be estimated by DGT, and moreover, 71 and 64% of the Hg accumulation in DGT and earthworm, respectively, was explained by a multiple regression model applying soil properties. Overall results demonstrate that DGT-measured Hg flux, related to the soil properties as well as Hg concentration, is a practical tool for predicting Hg bioavailability for earthworms inhabiting diverse types of soils.
E-mail nhviet86@gist.ac.kr