Tennessee Wastewater Operator Practice Exam

What chemical is most effective for controlling M. Parvicella?

1. Alum

2. Poly aluminum chloride

3. Calcium hypochlorite

4. Ferric chloride

The correct answer is: Poly aluminum chloride

The most effective chemical for controlling M. Parvicella is poly aluminum chloride. This chemical is a coagulant that is particularly effective at addressing nuisance algae and specific microorganisms like M. Parvicella in wastewater treatment processes. Poly aluminum chloride works by providing a positive charge that destabilizes and aggregates negatively charged particles, leading to effective flocculation and settling of the targeted microorganisms. The use of poly aluminum chloride is advantageous in wastewater treatment due to its ability to perform well across a range of pH levels, allowing for adaptability in different water conditions. It also has a lower chemical demand and residuals compared to some other coagulants, which is beneficial for maintaining water quality after treatment. While the other chemicals listed may have their own uses in wastewater treatment, they do not possess the same level of effectiveness specifically against M. Parvicella. For instance, alum and ferric chloride are effective coagulants but may not be as targeted as poly aluminum chloride when specifically addressing issues related to M. Parvicella. Calcium hypochlorite, primarily a disinfectant, does not function as a coagulant, making it less suitable for the control of microorganisms in this context.