Electromigration of microbial electron acceptors and nutrients: (II) Transport in groundwater

Abstract

Bioremediation in contaminated aquifers is often limited by the availability of microbial electron acceptors and nutrients. In this study, electromigration of the electron acceptor nitrate was assessed in sandy model soil mixed with groundwater from a contaminated site, and compared with previous results obtained in soil mixed with demineralized water. The specific nitrate transport rate in soil with groundwater at a voltage gradient of 2 V/cm and 0.5 g/L nitrate was 1.64 cm/h, and proved to be higher than in demineralized water (1.13 cm/h). The application of electrokinetic transport is a promising approach to enhance mass transfer in groundwater systems.

Keywords:

• Electromigration
• bioremediation
• groundwater
• nitrate
• sulfate
• transport rate
• mass transport

Acknowledgments

We gratefully acknowledge financial support by the Federal Ministry of Economics and Technology and the German Federation of Industrial Research Associations “Otto von Guericke” e.V. (AiF) (project no 15131 N). Svenja Lohner was supported by a scholarship of the German Economic Foundation (“Stiftung der Deutschen Wirtschaft”). We thank Hagen Steger and Roman Zorn for providing the electrokinetic test chambers. This study was supported by stimulating discussions with in the EU action COST D32.