Adjusting pH is an important step in the production of cosmetic formulations, liquid detergents, treatment of industrial wastewater or within biopharmaceutical drug manufacturing. The process itself is often very time intensive due to complex proton partitioning equilibria and represents a challenging control problem resulting from the intrinsic non-linearity of the pH value. Additionally, buffer chemicals, weak acids or bases that can donate or accept protons, often used in the formulations to maintaining the pH within a narrow margin upon acid/base addition, complicate the process of pH adjustment.