Before we begin, since sodium metabisulfite is known by many names, we will start by introducing the most common names.
- Sodium Pyrosulfite
- Acide disulfureux
- Sel disodique
- SMBS
*Note that the term "sodium" can be exchanged for " caustic ".
Its uses
This versatile product can be used as an antioxidant, food preservative, and even for photographic processing. As we are a water treatment company, we will only discuss its uses as an antioxidant in water treatment.
In the water treatment industry, sodium metabisulfite has many uses. Starting with its use as a reducer since it is often used as a deoxygenator. Then, its antioxidant capacity makes it an important part of the dechlorination stage or even during the pre-treatment of reverse osmosis.
En effet, le métabisulfite de sodium est très efficace pour la réduction du chlore libre et de la chloramine. C’est pourquoi ils sont souvent utilisés pour la déchloration ou dans le prétraitement des osmoses inverses. IL ne faut pas oublier que l’importance d’extraire les chloramines avant un traitement d’osmose inverse réside dans la durabilité des membranes osmotique. Pour en apprendre plus sur le sujet, vous pouvez consulter cet article.
In short, to learn more about sodium metabisulfite, we invite you to read this article presenting a comparison between 3 dechlorination technologies: activated carbon, sodium metabisulfite and UV irradiation.
How does SBMS work?
Simply put, the addition of sodium metabisulfite to water activates a chemical reaction that immediately attacks the targeted contaminant. As an example:
For free chlorine: Na2S2O5 + 3H2O + 2Cl2 -> NaHSO4 + 2HCl
For Chloramines: Na2S2O5 + 9H2O + 2NH3 +6Cl2 -> 6NaHSO4 + 10HCl + 2NH4Cl