Online identification and control of pH in a neutralization system

Obut S., ÖZGEN C.

INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH, vol.47, no.13, pp.4394-4404, 2008 (SCI-Expanded) identifier identifier

  • Publication Type: Article / Article
  • Volume: 47 Issue: 13
  • Publication Date: 2008
  • Doi Number: 10.1021/ie070492p
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Page Numbers: pp.4394-4404
  • Middle East Technical University Affiliated: Yes


pH control of a neutralization system for wastewater, where the input waste stream has variable properties in terms of acid concentration and flow rate, is investigated with different control algorithms utilizing an online identification technique. Performances of the designed controllers (model predictive (MPC), fuzzy logic (FLC), and conventional PI controller) are tested and compared mainly for disturbance rejection, set-point tracking, and robustness issues theoretically and experimentally on a laboratory-scale pH neutralization system. Additional experiments are done with original wastewater samples taken from an electronic-circuits manufacturing plant. All controllers' performances are found to be close, while adaptive MPC can be considered better compared to others due its constraint handling capabilities and FLC can be preferred because it can be used without an identification step.