PH the Hammett acidity function, "H", has been developed in connection with superacids. The concept of "unified pH scale" has been developed on the basis of the absolute chemical potential of the proton. This model uses the Lewis acid–base definition. This scale applies to liquids, gases and even solids. In 2010, a new "unified absolute pH scale" has been proposed that would allow various pH ranges across different solutions to use a common proton reference standard. Pure water is neutral. When an acid is dissolved in water, the pH will be less than 7 (25 °C). When a base, or alkali,
Acid mine drainage suitable for relatively small flows or less complex acid mine drainage. A calcium silicate feedstock, made from processed steel slag, can also be used to neutralize active acidity in AMD systems by removing free hydrogen ions from the bulk solution, thereby increasing pH. As the silicate anion captures H ions (raising the pH), it forms monosilicic acid (HSiO), a neutral solute. Monosilicic acid remains in the bulk solution to play many roles in correcting the adverse effects of acidic conditions. In the bulk solution, the silicate anion is very active in neutralizing H cations in the soil solution. While its