Fenton's Reagent requires soluble Fe2+ to form OH•. This optimal reaction occurs under relatively low pH conditions (., pH of 2 to 4). pH adjustment in the treatment area is often necessary to enable the oxidation process to proceed efficiently. This can be accomplished by either acidifying the hydrogen peroxide or by adding a chelating acid. Using a ferrous sulfate solution `simultaneously adjusts aquifer pH and adds the iron catalyst needed for Fenton's Reagent. Because of the low pH requirement, Fenton's Reagent treatment may not be efficient or effective in limestone geology or sediments with elevated pH levels or with significant capacity to.
