A NEW CATALYZED PERSULFATE ISCO AGENT: LAB AND FIELD TEST TO COMPARE IT WITH TRADITIONAL ACTIVATION SYSTEM

Abstract

This paper presents two independent tests, one lab test on a TPH contaminated site and the one field test on another site, aimed to analysed the different behaviour of Persulfox^TM and traditional base-activated persulfate. Tests have been done in two different institutes. The lab test has been conducted on a TPH contaminated soil and groundwater sample that has been treated by oxidant reagents, between which, base-activated persulfate and Persulfox^TM have been compared. The two reagents had similar behaviour with respect to COCs removal with a very good efficiency on aqueous phase and little effects on soil, but with more than 70 to 90% of product still present after 28 days test (able in this way to degrade COCs as they desorb from soil). SOD (Soil Oxidant Demand) test phase indicated a lower consumption for Persulfox^TM than for activated persulfate, and soil buffering test indicated different behaviours while adding an acid or a base. Field testing activities have been done by a double application on a hydrocarbon contaminated plume in Canada. They injected NaOH-activated persulfate and Persulfox^TM across two different plume’s sections. The aquifer was characterized by silty sands with medium permeability and sulfate reductive conditions and total HC concentration was 80 mg/l. Monitoring wells, groundwater sampling points and soil drillings have been used in order to monitor field parameters and COCs concentrations and define how the two products distribute and behave; looking at product distribution they had a similar behaviour while Persulfox^TM seemed to have a higher longevity with no need of further specific actions (as pH controlling) in order to keep it active. COCs concentrations went down in both cases but with higher efficiency in Persulfox field with no rebound seen in monitoring period.