How Fenton Improves Pretreatment？

In the treatment of difficult industrial wastewater — such as coking effluent, dye wastewater, phenol-containing chemical effluent, and high-strength pesticide wastewater—traditional biological processes often fall short.

The Fenton reaction, a classic advanced oxidation process (AOP), is now widely used in pretreatment stages, significantly improving the biodegradability of complex wastewater.

 

🔬 How the Fenton Reaction Works

The Fenton process relies on a catalytic reaction between ferrous ions (Fe²⁺) and hydrogen peroxide (H₂O₂) under acidic conditions, producing highly reactive hydroxyl radicals (•OH).

These radicals:

• Rapidly break down long-chain organic molecules
• Destroy aromatic structures
• Convert complex compounds into smaller, biodegradable intermediates

This makes Fenton a highly effective tool for degrading persistent organic pollutants before biological treatment.

 

🧪 Typical Fenton Treatment Process

1. Pretreatment Use screens, oil separators, and grit chambers to remove large particles and suspended solids.
2. pH Adjustment Lower pH to 2–4 using sulfuric acid. 👉 Optimal range: pH ≈ 3.5
3. Catalyst Addition Add ferrous sulfate heptahydrate (FeSO₄·7H₂O) to activate the reaction.
4. Hydrogen Peroxide Dosing Add H₂O₂ to generate hydroxyl radicals for rapid oxidation.
5. pH Neutralization After reaction, adjust pH back to neutral using caustic soda or lime.
6. Coagulation & Sedimentation Add coagulants like PAC and PAM to separate solids from treated water.

 

⚙️ Key Factors Affecting Fenton Efficiency

• pH control: Critical for •OH production—avoid too high or too low levels
• Catalyst dosage: Too little = underperformance; too much = color/mud issues
• H₂O₂ dosage: Balance is key—excess leads to waste or floating sludge
• Reaction time: 1.5–2 hours is ideal for complete degradation
• Temperature: Higher temps can speed up reactions, but be cautious with heat-sensitive systems

 

🏭 Application Scenarios & Recommendations

Fenton oxidation is widely used in coking, pesticide, and petrochemical wastewater due to its:

• High reaction efficiency
• Broad applicability
• Flexible operation

However, its success depends on precise control of reaction conditions. ⚠️ System design should be tailored to the specific wastewater characteristics.

 

✅ Final Advice

Fenton reaction isn’t just chemistry—it’s an engineering solution. If you need help with:

• Chemical dosing optimization
• Reactor design
• System integration for Fenton pretreatment

💬 Drop your questions in the comments or contact us for expert support.