Florida Wastewater Practice Test 2026 - Free Wastewater Certification Practice Questions and Study Guide

A good settling sludge typically consists of protozoa that contribute to the flocculation process in wastewater treatment. Free swimmers and stalk ciliates play a crucial role in this process. Free-swimming protozoa help to disperse and consume bacteria, which can enhance the aggregation of solids in the sludge. Stalk ciliates, on the other hand, have a stalk that allows them to attach to surfaces, helping to create a dense biomass that promotes settling. This combination aids in the formation of well-structured flocs, which are critical for effective sedimentation and clarification in treatment systems.

The other types of protozoa listed are less effective for creating good settling biomass. Flagellates and amoebae, while present in microbial communities, do not significantly contribute to the formation of dense flocs necessary for optimal settling. Filamentous and non-flagellates might introduce structural elements to the sludge but could lead to bulking if present in excess. Single-celled and colonial protozoa can contribute to the overall biomass; however, they do not specifically enhance the settling properties to the same extent as the free swimmers and stalk ciliates. Thus, the composition of protozoa in question A directly supports the goals of sedimentation in wastewater