Florida Drinking Water Operator "B" Practice Test

What should be done when the temperature of the influent source water decreases and floc quality deteriorates?

1. Increase chemical dosage

2. Decrease the flow through the plant to increase detention time

3. Turn off the flocculators

4. Use warmer water for filtration

The correct answer is: Decrease the flow through the plant to increase detention time

When the temperature of the influent source water decreases and the floc quality begins to deteriorate, one effective response is to decrease the flow through the plant to increase detention time. This strategy allows for more extended interaction between the chemicals used for flocculation and the particles in the water. In cooler water conditions, chemical reactions can slow down, and floc formation may not be as efficient. By reducing the flow, water remains in contact with the flocculants longer, enhancing the chances for better agglomeration of particles and improving floc quality overall. This approach recognizes that chemical processes related to coagulation and flocculation can be temperature-dependent. The improved contact time can compensate for the reduced kinetic energy in the colder water, ultimately facilitating better floc formation and settling. Other options may not adequately address the issue of declining floc quality in cold water. For example, simply increasing the chemical dosage may not guarantee improved floc formation under colder temperatures and could lead to overdosing, which may create other water quality issues. Turning off the flocculators would eliminate the mixing necessary for flocculation, likely exacerbating the problem instead of solving it. Using warmer water for filtration is generally not feasible or practical, as water temperature cannot