Texas Wastewater Class B Practice Exam

What type of treatment would involve the use of trickling filters?

1. Primary Treatment

2. Secondary Treatment

3. Preliminary Treatment

4. Tertiary Treatment

The correct answer is: Secondary Treatment

Trickling filters are a type of biological treatment process used in wastewater treatment systems, specifically classified under secondary treatment. In this process, wastewater is passed over a bed of stones or synthetic media, where microorganisms attach and form a biofilm. These microorganisms then break down organic matter in the wastewater as it trickles through the filter. This method effectively reduces the concentration of pollutants and organic materials, making wastewater cleaner before it moves on to further treatment processes. Primary treatment typically involves physical processes such as sedimentation to remove larger solids, while preliminary treatment focuses on removing debris and large particles to protect equipment. Tertiary treatment is aimed at further polishing the water, addressing any remaining contaminants after secondary treatment. Trickling filters, aligning with secondary treatment, are vital for biological decomposition of residual organic materials, thus playing a crucial role in the overall wastewater treatment process.