Due to tougher legislation and more frequent inspections, environmental policy has become increasingly important in the corporate world.
Treating water with CO₂ is a very promising technique that offers many technical, ecological, and financial advantages.

CO₂ is a natural gas present in the atmosphere in low concentrations. When CO₂ is dissolved in water it forms hydrogen carbonate, also known as carbonic acid gas (H₂CO₃). This weak acid is the only mineral acid that is present in natural waters. Carbonic acid reacts with the base elements in the water and neutralizes alkaline water.

Advantages:

Compared to traditional strong acids (H₂SO₄ and HCl) CO₂ offers numerous advantages:

1. Natural product:
   • Part of the atmosphere (0,035%)
   • Water-friendly
2. Ecologically-sound product:
   • Non-toxic and non-corrosive (to personnel and local residents)
   • Does not introduce polluting elements in the water
   • No excessive acidification of the water (flat neutralization curve -> no fluctuating pH level)
   • CO₂ neutralization helps to reduce the greenhouse effect (CO₂ hat would otherwise be discharged is used in the neutralization process)
3. Smaller investment:
   • More homogeneous pH values are obtained than with H₂SO₄; leading to a more correct dosage,
   • Easier to service the installation: less sediment as Na₂CO₃ is more soluble in water and CO₂ is a non-corrosive product.
   • No special safety measures required
   • No special equipment required since CO₂ is a non-corrosive product, unlike strong acids.

Some applications:

• Treatment of industrial waters:
  • Neutralizing the pH level of waste water before it is discharged or biologically treated
  • Optimal pH regulation in the water before it is physico-chemically treated (e.g. flocculation, etc.)
  • CO₂ as an organic source of carbon dioxide in stead of carbonates
• Treatment of drinking water
• Water remineralization
• Treatment of process water
  • Restoring chemical balance in, for example, scaling water
  • Regenerating ion changers using denitrifying resins
• Treatment of swimming pools

Simple installation:

The installation consists of the following parts:

• CO₂-tank
• The installation consists of the following parts CO₂
• CO₂ injection system (e.g static mixer)

The CO₂ dosage can be regulated directly in the discharge tube. Another possibility is that the water to be treated is collected in a basin (well), from which a circulation pipe starts circulating the water until the desired pH level is reached. Afterwards, the water can be drained.