Alkalinity and the Carbonate System
Definition
The bicarbonate, carbonate, and hydroxide buffering system that governs pH stability and produces carbon dioxide in steam and condensate lines.
Bicarbonate is generally soluble, but carbonate species quickly deposit with calcium and iron, and the system can drive boiler carryover. Maintaining hydroxide alkalinity in phosphate-treated boilers ensures magnesium precipitates as a fluid sludge rather than sticky scale. Alkalinity is controlled through acid treatment, reverse osmosis or deionization, and dealkalization.
Related concepts
pH Control · Precipitation · Carbonate Scale Formation
Part of The Blueprint of Water · 🧪 chemistry