Ammonium Bisulphite Supplier South Africa

What Is Ammonium Bisulphite?

Ammonium bisulphite (ammonium hydrogen sulfite, NH₄HSO₃) is an inorganic reducing salt available as a clear to pale yellow aqueous solution or white powder. It is a strong oxygen scavenger and reducing agent — it rapidly consumes dissolved oxygen through the reaction: NH₄HSO₃ + ½O₂ → NH₄HSO₄ (ammonium bisulfate). This reaction is much faster than that of sodium sulfite with dissolved oxygen, particularly at low temperatures (near ambient) without catalyst, making ammonium bisulphite preferred in oilfield and industrial water applications where rapid oxygen scavenging is needed at injection pressure and ambient-to-moderate temperatures.

Oilfield Oxygen Scavenging Application

In oilfield water injection systems, dissolved oxygen in the injection water is a major cause of corrosion of injection pipelines, wellhead equipment, and injection wellbores. Even trace dissolved oxygen (>10 µg/L) in injection water greatly accelerates SRB growth and pitting corrosion. Ammonium bisulphite is dosed ahead of the injection pump or into the injection line to remove oxygen before it can cause damage. The ammonium ion released on reaction may provide mild bacteriostatic benefit in some systems. The solution form of ammonium bisulphite is easy to inject as a chemical (compared to sodium sulfite powder which requires dissolving) and is fully compatible with produced water chemistry.

Industrial Process Water and Other Applications

In industrial process water systems, ammonium bisulphite is used in reverse osmosis pre-treatment to remove residual oxidants (chlorine, chloramines) from the feed water ahead of polyamide RO membranes — RO membranes are highly sensitive to oxidant damage, and ammonium bisulphite rapidly reduces chlorine residuals to harmless chloride. In boiler feedwater systems, it supplements or replaces sodium sulfite for oxygen scavenging at lower temperatures. Terracore Chemicals supplies ammonium bisulphite as aqueous solution (60–65% active) in 25 kg and 200 kg drums.