What is a degasser in water treatment?

A degasser is a water treatment system designed to remove dissolved gases such as carbon dioxide (CO₂) and, in suitable applications, hydrogen sulphide (H₂S). It is commonly installed after RO and before DI, EDI, or other high-purity water treatment stages.

Why is a degasser used after RO?

RO membranes remove dissolved salts very effectively but do not reject dissolved gases such as CO₂ as effectively. A degasser removes this residual CO₂ from the RO permeate before it reaches downstream ion exchange or EDI equipment, helping reduce the treatment load and improve system performance.

Does a degasser remove CO₂ from water?

Yes. A properly designed degasser transfers dissolved CO₂ from the water into another gas phase, typically using air in a packed tower or a vacuum/sweep gas in a membrane degasser. The required removal level depends on the application and system design

Can a degasser improve EDI performance?

Yes. Excess dissolved CO₂ can increase the load on an EDI system and affect its ability to produce high-purity water efficiently. Reducing CO₂ before EDI can provide a more suitable feed stream and help maintain stable operation. The required feed-water quality should always be confirmed with the EDI manufacturer.

How do I know if my water treatment plant needs a degasser?

A degasser may be beneficial if your RO permeate contains significant dissolved CO₂, your anion exchange resin is exhausting faster than expected, your EDI system is struggling to maintain the required water quality, or you are experiencing low-pH and corrosion issues. A water analysis covering parameters such as alkalinity, pH, CO₂, conductivity and TDS can help determine whether degassing is appropriate.

Degasser in Water Treatment | CO₂ Removal Tower | Industrial Water System