Wastewater Treatment Operator Certification Practice Test

What is used to control filamentous organisms?

1. Polymer

2. Sulfur Dioxide

3. Coagulant

4. Chlorine

The correct answer is: Chlorine

Controlling filamentous organisms in wastewater treatment is crucial because these organisms can lead to issues such as bulking, which affects sedimentation and overall treatment efficiency. Chlorine is a strong oxidizing agent that can effectively reduce the population of filamentous bacteria. By using chlorine in appropriate doses, operators can minimize the growth of these filamentous organisms, thus helping to maintain the desired biomass characteristics in the treatment process. This disinfection method works by introducing chlorine into the wastewater, which reacts with and destroys the cellular structure of unwanted filamentous bacteria. Chlorine's efficacy as a biocide allows for the targeted control of these problematic organisms while also achieving broader disinfection objectives. In comparison, other options such as polymer, sulfur dioxide, and coagulants have different primary applications. Polymers are typically used for flocculation to aid in sedimentation and do not specifically target filamentous organisms. Sulfur dioxide is commonly used in some industrial processes but is not a standard method for biological control in wastewater treatment. Coagulants are mainly used to remove suspended solids and do not directly combat the growth of filamentous bacteria. Hence, the use of chlorine stands out as a targeted method for controlling filamentous organisms effectively.