pH neutralization process plants are widely used particularly in the wastewater treatment and process industries such as biotechnology, chemical processing and pharmaceuticals. The control of pH neutralization is recognized as a difficult problem due to the highly nonlinear characteristics of the process. The need to regulate the pH value within a specific level arises from environmental legislative and quality standards. On the other hand, pH control process introduces numerous challenges in control strategies. Certainly, this fact makes the development of this pH neutralization process control more interesting. This study will focus on control methodologies of pH neutralization process. © 2011 IEEE.