Controlling of neutralization processes is a classical problem beyond many common control techniques available today due to their strong nonlinearity and extreme sensitivity to disturbances. This paper proposes an adaptive fuzzy control scheme for wastewater neutralization process control. A standard Mamdani type fuzzy system is constructed to describe the nonlinearity of the process and the parameters in the fuzzy system are tuned online using the least square algorithm with deadzone. The controller is designed based on the fuzzy model and the control action is computed by exploiting the special features of the fuzzy system. Simulation results are given in control of the acidity in the continuous flow of an industrial wastewater treatment system.