Texas Wastewater Class B Practice Exam

Apart from disinfection, what are other uses of chlorine in wastewater treatment?

1. Increases pH and temperature

2. Fortifies nutrients and chemicals

3. Reduces BOD, odor, algae growth, and helps with grease

4. Enhances aerobic bacteria activity

The correct answer is: Reduces BOD, odor, algae growth, and helps with grease

The selection is appropriate because chlorine serves multiple pivotal roles in wastewater treatment beyond disinfection. It is effective in reducing biochemical oxygen demand (BOD), which is crucial since BOD levels are indicative of the amount of organic matter in water and direct indicators of the pollution load. Chlorine is also effective in reducing odors, which can arise from anaerobic decomposition processes in wastewater. Additionally, it helps control algae growth, as excessive algae can lead to water quality issues and further consume oxygen in treatment processes. The ability to address grease is also significant since grease can complicate wastewater treatment and lead to clogs in systems. Other options do not align with the widely recognized functionalities of chlorine in wastewater treatment processes. Increasing pH and temperature is not a primary role of chlorine; instead, these parameters are often managed through different chemical treatments and environmental controls. Fortifying nutrients and chemicals isn't a direct function of chlorine, as it does not add nutrients to the wastewater. Enhancing aerobic bacteria activity specifically is more related to aeration processes and not a recognized role of chlorine, which can sometimes even inhibit these bacteria's activity if concentrations are too high.