Competitive sorption and desorption between BDE-47 and BDE-99 by different river- and farmland-based aquifer media

Abstract

Two main PBDEs that have potential endocrine disrupting properties—2,2,4,4′-tetrabromodiphenyl ether (BDE-47) and 2,2′,4,4′,5-tetrabromodiphenyl ether (BDE-99)—have been detected in environmental samples and have drawn public attention. In a single solute system, three aquifer media, Beijing river aquifer media, Beijing farmland soil, and Fujian farmland soil (FN), with different properties were collected as the main sorbents to investigate the sorption and desorption characteristic of BDE-47. The results indicate that a two-compartment first-order model could adequately describe the sorption kinetics of BDE-47. FN has the largest adsorption capacity, showing that a high organic matter content could improve the soil adsorption capability. In binary-solute systems, a series of BDE-99 with different concentration suppresses the sorption of BDE-47. The result indicates that the sorption capacity of BDE-47 significantly decreases with the increasing concentration of BDE-99, and the decreasing tendency becomes more obvious when the content of BDE-47 is high. By contrast, BDE-47 does not show a competitive sorption effect on BDE-99 sorption. The BDE-47 desorption from soils exhibits hysteresis with the addition of BDE-99, especially for FN. These results could be used to predict a potential pathway for the removal of PBDEs and for the evaluation of ecological risks when using reclaimed municipal wastewater.

Keywords:

• BDE-47
• Sorption
• Desorption
• Binary-solute system
• Competitive adsorption

Acknowledgments

The authors gratefully acknowledge financial support from the Fundamental Research Fund for the Central Universities (No. 2015-04), Beijing Natural Science Foundation (8132040) and the Fundamental Research Funds for the Central Universities (TD2013-2).

Notes

Presented at the 8th International Conference on Challenges in Environmental Science & Engineering (CESE-2015) 28 September–2 October 2015, Sydney, Australia