When tank alarms are activated for the pH system, what should you check first if Tank 2's pH is 5.00?

• A. Tank 2's mixer
• B. The calibration of the pH probe
• C. The reagent levels
• D. The final effluent pH

Answer: (A)

When tank alarms are activated for the pH system, checking Tank 2's mixer first is a logical step because inadequate mixing can lead to localized pH variations that may cause the alarm to trigger. Tank mixers ensure that the chemicals and wastewater are evenly distributed, which is essential for maintaining a consistent pH level throughout the tank. If the mixer is malfunctioning or not operating as intended, it may result in misleading pH readings and could prevent proper chemical reactions necessary for pH stabilization.

Addressing the condition of the mixer allows operators to determine whether the pH issue is due to ineffective mixing rather than other potential issues, such as calibration or reagent problems. Although calibration and reagent levels are critical for accurate pH measurement and adjustment, confirming that the mixer is functioning properly helps rule out one of the most significant factors affecting pH consistency right away.