Controlled release of persulfate (S2O82-) and ferrous ion (Fe2+) as its activating agent is a new, desirable method for groundwater remediation. Persulfate, a strong oxidizer, has shown great potential in the treatment of many contaminants due to its stability and relatively long shelf life compared to other strong oxidizers such as H2O2. A sustained release of persulfate in groundwater remediation is desirable. Controlled release of Fe2+ ions is used to activate persulfate. The viability of controlled release of S2O82- and Fe2+ has been investigated. Potassium persulfate and ferrous sulfate were each incorporated into different silica matrices (i.e., zeolite and diatom) in the form of solid, cylindrical pellets. Decomposition of trichloroethylene (TCE), a dense non-aqueous phase liquid (DNAPL), by our system is used as an example. As an option to further prolong the release time, sol-gel has been used as internal pellet support and/or surface coating. Diffusion profiles of S2O82- and Fe2+ from the structurally different pellets have been determined. Batch treatment has been performed on a 15 ppm TCE solution. After treatment by the pellets, determination by GC-MS-SIM showed TCE concentrations below the method limit of detection (LoD) of 50 ppb.

Controlled release of persulfate and Fe2+ ions for contaminant treatment

2019 Spring National Meeting

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