In Situ Chemical Oxidation of Contaminated Soil and Groundwater Using Persulfate: A Review

Abstract

Persulfate is the newest oxidant that is being used for in situ chemical oxidation (ISCO) in the remediation of soil and groundwater. In this review, the fundamental reactions and governing factors of persulfate relevant to ISCO are discussed. The latest experiences for ISCO with persulfate are presented, with a focus on the different activation methods, the amenable contaminants, and the reactions of persulfate with porous media, based primarily on a critical review of the peer-reviewed scientific literature and to a lesser extent on non-reviewed professional journals and conference proceedings. The last sections are devoted to identifying the best practices based on current experience and suggesting the direction of future research.

KEY WORDS:

• remediation
• aquifer
• activation
• sulfate radical
• oxidation

ACKNOWLEDGMENTS

This work was supported by the Technical University of Denmark (DTU) through a Ph.D. scholarship for Aikaterini Tsitonaki. We thank Torben Dolin (DTU) for help with the artwork and post-doctoral researcher Dr. Saebom Ko from East Tennessee State University.

Notes

* Pseudo first-order rates for consumption of persulfate ion (s^{− 1}). The reactions may have been mediated by the sulfate radical, but the reported rates are calculated based on the Δ S₂O₈ ^{2 −}.

* Effective 1-D transport distances are estimated based on the assumption that persulfate is effective until its concentration is 10% of the initial dose (C₀).