The drainage neutralization treatment system is for neutralizing pH and discharging drainage water with strong alkali or strong acid emanating from construction sites, research facilities, hospitals and various types of factories.

The neutralization process of raw water can work on automatic control in response to the fluctuation in pH of water inflow with compatible controller SR23 and recorder SR186A. For pH not to deviate from standard value, a control range is set at, e.g., pH6.5–8.0, and an alarm goes off if the value goes beyond the control range. To set off the alarm, the higher limit value and lower limit value of SR23 are set on event (refer to figure below). Automatic serial recording of discharge water pH is possible.