What is the main function of a sedimentation tank?

The main function of a sedimentation tank is to promote solid-liquid separation. This process is essential in wastewater treatment, as it allows solid particles suspended in the wastewater to settle out of the liquid phase due to gravity. In the sedimentation tank, the flow of water is slowed down, providing sufficient time for the heavier particles to sink to the bottom, forming sludge, while clearer water can be collected from the top.

The design and operation of sedimentation tanks focus on optimizing the conditions for this separation to occur efficiently, ensuring that the treated water can proceed to further treatment stages with a reduced solid content. This step is vital for maintaining the effectiveness of subsequent treatment processes and protecting the environment.

The other options, while related to wastewater treatment, do not accurately describe the primary function of a sedimentation tank. For example, increasing flow rate pertains more to the hydraulic design of a treatment system rather than the settling of solids. Treating chemical spills typically involves different technologies and methodologies focused on hazardous materials. Recycling wastewater refers to processes that involve reclaiming treated water for reuse, which is not the primary role of a sedimentation tank specifically.