Calculation of pH Values for Mixed Waters

Abstract

Mixing of waters with different compositions is a common phenomenon. The pH of mixed water can be calculated by introducing charge neutrality equation into the equations for equilibrium distribution calculation of species in water. In this paper, the equations thus obtained were solved by golden section method. To verify the calculation method, laboratory experiments were done for three sets of mixing water. The results showed the calculated pH values are in good agreement with measured ones.

Theoretical Investigation of Groundwater pH

“…The dissociation equilibriums have taken place. The constant of the equilibrium may be calculated by approximation [2]. The other problem of the direct calculation is the activity coefficient, which is usually calculated by the extended Debye-Huckel equation.…”

“…In this method, all inions and cations, including H+ and OH-are taken into account. The equitation is calculated numerically by different methods such as the quadratic interpolation method or Golden section [2]. Accuracy pH calculation checking is challenging due to the accuracy of pH measurement.…”

“…The development of the wide using method is a key to progress in calculation prediction methods. The direct method of mass balance should be used as a standard one [2]. The equitation should be neutral regardless of the number of anions or cations that take place.…”