Fenton's reagent is the name given to a solution of hydrogen peroxide and an iron catalyst, such as iron(III) sulfate or chloride, very useful to destroy hazardous organic compounds, such as acetonitrile, benzene, chloroform, tetrachloroethane, trichloroethylene, etc.
Fenton's reagent will convert benzene into phenol:
- C6H6 + FeSO4 + H2O2 → C6H5OH
Some chemists think Fenton's reagent contains iron(IV).
A disadvantage of using the Fenton oxidation to remove organic contaminants is the formation of Fe(OH)3 precipitate, which contains large quantities of adsorbed organic compounds. Limiting the amount of Fe3+ added will limit the formation of the undesired hydroxide.
Fenton's reagent works best under UV light, most of the time the process is photochemical.
The main drawbacks of the Fenton process are the volatilization of the target compound (waste e.g.) during the oxidation process, due to the resulting gasses from the oxidation, foaming, splashing, all which can be reduced if the target compound is added in small amounts over time or as diluted solution. However, this also means that Fenton's solution cannot be used for safely disposing of bulk quantities of waste.
Fenton's reagent is a yellow-orange solution.
Fenton's reagent is a strong oxidizing mixture and proper protection should be worn when handling it.
Fenton's reagent should be produced and used in situ. If needed for longer periods of time, it should be stored in containers without hermetic seal, to prevent a pressure buildup of the oxygen from the decomposing peroxide.
Used Fenton's reagent can be poured down the drain, after all the peroxide was neutralized. Just be sure to check if there aren't any more organic residues that escaped the oxidation.