The effects of interaction between vermiculite and manganese dioxide on the environmental geochemical process of thallium.

Author(s) Chen, M.; Wu, P.; Li, S.; Yang, S.; Lin, Z.; Dang, Z.
Journal Sci Total Environ
Date Published 2019 Jun 15
Abstract

The interaction among various soil minerals can significantly impact on the environmental geochemical process of contaminants. Therefore, this study investigated the effects of interaction between vermiculite (VER) and manganese dioxide (MnO) on the migration and transformation of Tl(I). The VER exhibited typical layered structure and MnO possessed a flower-like structure with serious reunion phenomenon, while the production of interaction between vermiculite and manganese dioxide, labeled VER-MnO, illustrated as fish scales evenly spread over a large sheet, suggesting that MnO could triumphantly be anchored on the VER and the aggregation of MnO was prevented. Compared with the pure MnO, VER acted as template substrate contributed the higher specific surface area (298.18 m·g) and the oxidation degree of Mn. VER-MnO showed the highest fixation capacity (144.29 mg·g) than other two materials in the order VER-MnO > MnO > VER, and there was no risk derived from Mn dissolution. The influence mechanism of VER-MnO on Tl(I) migration and transformation lied in immobilization, ion exchange and oxidization. Fixed-bed column immobilization experiments showed that VER-MnO could purify drinking water contaminated by Tl (20 μg·L) and the effective breakthrough volumes were 900 bed volumes until reaching the maximum limits allowed in drinking water (0.1 μg·L). VER-MnO excellently catches Tl to prevent groundwater pollution. This study provides a theoretical guidance for environmental fate and restoration of soil heavy metal pollution.

DOI 10.1016/j.scitotenv.2019.03.079
ISSN 1879-1026
Citation Chen M, Wu P, Li S, Yang S, Lin Z, Dang Z. The effects of interaction between vermiculite and manganese dioxide on the environmental geochemical process of thallium. Sci Total Environ. 2019;669:903-910.