Prediction of pH

Assume we have makeup water analysis.

How to evaluate the value of pH in recirculation (RR) water?

In many case pH of RR water depends on alkalinity content.

pH = A + B * log10(Alkalinity in RR as ppm of CaCO3)

If there are no analysis of RR water you can assume

A = 4.17

B = 1.717

If you have analysis of RR water you can determine parameters A and B by LSQM or by plotting dependency ph ~ log10(Alk). And also evaluate applicability of this formula to your system

If calculated pH is significantly higher than real pH you can suspect some leakages or can think about possible reasons.

Let assume that we do not have RR water analysis at all. In this case we can estimate RR alkalinity from makeup alkalinity

Alkalinity(RR) = Alkalinity(MU) * Cycles

If we know A and B it is possible to roughly estimate H2SO4 consumption in case of pH control to keep pH

Calculations could be found in Colab Notebook (https://colab.research.google.com/drive/1uN2zElI43uj6dLVq6DSg2tTxFmeK7-eV?usp=sharing). If you want to change anything choose "Save as" to save it to your Google account