Chemical Demand

Definition

The consumption of a treatment chemical driven by a form-change reaction whose rate scales with a shifting mass balance.

When dissolved oxygen load increases, sulfite demand increases proportionally, and when cycles of concentration rise, inhibitor demand rises proportionally. These are not mysterious consumption events but form-change consequences of a shifted mass balance. Restoring a residual by simply turning up a pump treats the symptom without addressing the changed balance that raised demand.

Related concepts

Sulfite Oxygen Scavenging · Cycles of Concentration · Biocide Efficacy

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Part of The Blueprint of Water · 🧪 chemistry