Sodium bisulfite

Sodium bisulfite is a common reducing agent in the chemical industries. As it readily reacts with dissolved oxygen:

2 NaHSO3 + O2 → 2 NaHSO4

It is usually added to large piping systems to prevent oxidative corrosion. In biochemical engineering applications, it is helpful to maintain anaerobic conditions within a reactor. Sodium bisulfite should not be confused with sodium bisulfate which is used as a pH lowering chemical for swimming pools.

In wastewater treatment, sodium bisulfite is often added following disinfection with a chlorine solution to neutralize the residual chlorine before discharging the treated effluent.

Reporting

Reference: ENS 46627

See also

• Sodium metabisulfite
• wikipedia:Sodium bisulfite