By removing iron, the filter not only improves the taste, odor, and clarity of water but also helps protect plumbing systems and household equipment, ensuring cleaner, safer, and more reliable water for everyday use.

🌊 Why Iron Removal is Needed

• High iron in water (>0.3 mg/L) causes:
  • Reddish-brown stains on clothes, utensils, plumbing.
  • Metallic taste, odor.
  • Clogging of pipes and RO membranes. romotes iron bacteria growth (slimy deposits).
  • Not suitable for drinking or industrial use (boilers, food processing, pharma, etc.).

🏭 Iron Removal Plant – Basic Process

An Iron Removal Plant removes dissolved and precipitated iron from water. The technology depends on form of iron (dissolved ferrous vs precipitated ferric) and concentration.

1. Aeration + Filtration (Most Common)

• Process: Water is aerated (exposed to air, cascade/aerator/diffuser) → dissolved ferrous iron (Fe²⁺) oxidizes to ferric iron (Fe³⁺) → forms insoluble rust particles → filtered out in a sand/dual media filter.
• Technology:
  • Cascade aerator, tray aerator, or pressure aeration.
  • Filtration with graded sand, manganese greensand, or Birm media.
• Best for: Iron < 10 ppm, low manganese.

2. Manganese Dioxide Media (Greensand, MnO₂, Birm, Pyrolox)

• Media coated with manganese dioxide oxidizes ferrous iron directly on contact.
• Often regenerated with KMnO₄ (Potassium Permanganate) or chlorine.
• Very effective for both iron and manganese removal.
• Best for: Higher iron/manganese levels, complex water chemistry.

3. Chemical Dosing + Filtration

• Oxidants added (chlorine, ozone, sodium hypochlorite, hydrogen peroxide).
• They convert ferrous to ferric → precipitate removed in clarifier or sand filter.
• Best for: High iron (>10 ppm), industrial scale, when disinfection is also required.

4. Pressure Filters (Multimedia / Dual Media)

• Compact units where pre-treated water passes under pressure through layers of sand, anthracite, garnet, or activated carbon.
• Removes oxidized iron, turbidity, some organics.
• Best for: Small industries, institutions.

5. Biological Iron Removal

• Certain bacteria (e.g., Gallionella, Leptothrix) oxidize iron naturally.
• Biofiltration units use sand/gravel beds colonized with these bacteria.
• Eco-friendly, low chemical cost, but slower and requires stable operation.
• Best for: Municipal plants, rural areas with limited chemicals.

🔧 Typical Components of an Iron Removal Plant

• Feed Pump – draws raw water.
• Aerator / Oxidation Unit – cascade, tray, pressure aeration, or chemical dosing.
• Retention Tank – allows oxidation & precipitation.
• Iron Removal Filter (Pressure Vessel) – FRP/MS vessel with media bed (sand, manganese greensand, Birm, activated carbon, etc.).
• Backwash System – removes trapped iron sludge from the filter media.
• Post-Treatment (optional) – softener, RO, UV, or chlorination, depending on final use.

✅ Advantages of Iron Removal Plants

• Removes iron, manganese, turbidity, odour.
• Protects downstream equipment (RO membranes, boilers).
• Improves taste and clarity.
• Low operating cost (for aeration + filtration systems).

⚠️ Challenges

• Regular backwashing needed to avoid clogging.
• Media replacement required periodically.
• High iron (>20–30 ppm) may need multi-stage treatment.
• Iron bacteria can foul filters if not controlled.