Josh Jondro – Chemical Engineer
Wastewater Management Team

As discussed in the August Newsletter, a Fully Automated Industrial Wastewater Pretreatment System will shutdown and temporarily holds wastewater for proper treatment if an out-of-spec condition, an excursion, is detected. These systems require checks only twice a week and an operator on-call. All other systems require a daily operator inspection.

Fortunately, a well designed system requires minimal time and attention to maintain proper function. Maintaining the system safety, chemical inventory, cleaning and calibrating the pH sensor are the most critical daily pH system operator responsibilities. A daily 2-stage active pH Neutralization System daily system check should include:

• Get a general feeling for the system operation. Are there any observable leaks or safety hazards? Is the system louder than normal? Are the pH analyzer/controller currently operating as required?
• Next review the data recorder. Has there been an excursion since the last check? If there has been an excursions system troubleshooting is required.
• Fill out all required paperwork including daily totalized flow and any excursion details (duration and the maximum out-of-spec pH).
• Check the mixers. Are they functioning as expected, or are they hotter or louder than normal? Is the tank agitating sufficiently?
• Check the chemical level in each dispensing drum or day tank. Is there enough chemical, or should more be ordered?
• Ensure the chemical metering pumps are powered and primed. Energize the pumps and use the pH analyzer control to simulate a pH value at which the pumps should respond. Observe the pump injecting chemical into the tank. Does the pH change after exiting the simulation mode?
• Confirm the pH sensors are clean and calibrated to detect changes in pH quickly. Clean the sensors as frequently as required, usually weekly. Check the pH calibration; if the measurement is off calibrate the sensor. A drifting pH reading is a good indication that a pH probe replacement is required.

If this process is followed daily, an Operator can predict when preventive maintenance is needed. If each item on this list is completed daily your pH Neutralization System will always operate as efficiently as it was designed.