Elevated Sulfate vs. Enhanced Reductive Dechlorination

Author: Craig Sandefur, Vice President of Technical Services – REGENESIS

A recent technical paper entitled “Chloroethene Biotransformation in the Presence of Different Sulfate Concentrations” by Marina Pantazida, et al. and published in the Winter 2012 Edition of Groundwater Monitoring and Remediation makes a number of  interesting observations about enhanced reductive dechlorination (ERD) under elevated sulfate conditions. The authors clearly provide a recommended upper limit for sulfate (250-300 mg/L) for complete dechlorination to proceed. Of interest to me is their observation that sulfate reduction and reductive dechlorination (RD) proceed concurrently in most studies. This observation is consistent with those of us that have long thought that removal of all sulfate does not have to happen prior to the onset of RD or in order for RD to proceed to completion. For more information on this paper visit the National Groundwater Associations website at ngwa.org  to view their online archive or order to order a copy of Groundwater Monitoring and Remediation.