Tennessee Wastewater Operator Practice Exam

If you noticed poor solids settling in the clarifier and solids overflow into the chlorine contact chamber, what would you do if the dilated settleometer showed improved settling?

1. Decrease sludge wasting

2. Increase sludge wasting

3. Change the chemical dosage

4. Alter the flow rate

The correct answer is: Increase sludge wasting

When poor solids settling occurs in a clarifier, it can lead to solids overflow into downstream processes, such as the chlorine contact chamber. This situation can compromise the efficiency of the treatment process and lead to potential compliance issues. The settleometer is a useful tool for assessing the settling characteristics of the sludge in the system. If the settleometer shows improved settling, it indicates that the settling characteristics of the sludge have improved, which is a positive development. In this context, increasing sludge wasting is the appropriate action. By increasing the amount of sludge wasted from the system, you are helping to maintain a healthy balance of solids in the clarifier. This can enhance the overall performance of the system, as it reduces the potential for solids to overflow by ensuring that the solids loading remains manageable. This choice is further supported by the fact that when solids settle more effectively, it often suggests that the sludge blanket in the clarifier is in a good state and could handle some additional removal to optimize conditions. This proactive approach can prevent future instances of solids overflow and improve process reliability.