Water and Wastewater Terms Beginning P

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pH (pronounce as separate letters)

An expression of the basic or acidic condition of a liquid. Mathematically, this is equivalent to the negative of the base 10 logarithm of the hydrogen ion concentration {H⁺}. If {H⁺} = 10^–6.5, then the pH = 6.5. The pH range is 0–14, where 0 is most acidic, 7 neutral, and 14 most basic.