The Fenton process is an advanced oxidationprocess (AOP) based on the generation of highly reactive hydroxyl radicals (OH-). These radicals oxidize organic compounds in wastewater and convert them into less harmful products such as water and carbon dioxide. The process was named after Henry J. H. Fenton, who described the reaction of hydrogen peroxide (H₂O₂) with iron(II) ions (Fe²⁺) in 1894.

Chemical basics

The reaction of the Fenton process takes place in several steps:

1. Formation of hydroxyl radicals:

   In this process, hydrogen peroxide is split into hydroxyl radicals and hydroxide ions by iron(II) ions.

2. Regeneration of the iron(II) ions:

   This regeneration enables the continuous production of radicals.

Technical implementation

The Fenton process typically takes place under acidic conditions (pH 2.5-4), as the reaction takes place optimally at this pH value. The core components include:

• Hydrogen peroxide (H₂O₂): The oxidizing agent.
• Iron(II) salts: Catalyst, often in the form of iron sulphate (FeSO₄).
• Reaction tank: Made of corrosion-resistant materials, as the acid and peroxide create aggressive conditions.

Advanced procedures

• Fenton-like processes: Use alternative metal catalysts such as copper or manganese.
• Photo-Fenton: UV light is added to increase the formation of radicals.