LABVIEW is a powerful and versatile graphical programming language that
had its roots in operation, automation control and data acquisition of the system. The pH control system of a non-linear wastewater treatment unit, contains heavy metals (Cu, Cr, Cd, Fe, Ni and Zn), had been developed depending on dynamics behavior of the process. The pH value of wastewater is change by addition chemicals (lime or Na2S). The semi-batch pH process system dynamically behaved as a first order lag with dead time. The tuning of control parameters was carried by
several methods; Internal Model Control (IMC), Minimum (ITAE) criteria and Adaptive mode. Since the process was fast, the Integral of Absolute of Error (IAE) criteria was used to compare between the above tuning methods. Adaptive control was the best and effective to determining the values of proportional gain (Kc), Integral time constant (t I) and Derivative time constant (t D ).PI mode was found to be the best for control the fast pH process.