Which process is used to separate solids from liquids in wastewater treatment?

In wastewater treatment, the separation of solids from liquids is effectively achieved through the process of sedimentation. This process relies on the principle of gravity, allowing heavier particles to settle at the bottom of a tank, forming a sludge layer. As the solids settle, the clearer liquid, known as supernatant, can be collected for further treatment or discharged.

Sedimentation is a key step in the primary treatment phase, where large solids are removed from the wastewater before it undergoes additional treatment processes. By allowing enough time for the solids to settle, sedimentation helps reduce the overall pollutant load in the wastewater, making subsequent treatment steps more efficient.

While filtration also serves to separate particles from liquids, it operates differently by forcing water through a medium that captures finer solids. Coagulation is a pretreatment method that involves adding chemicals to promote the aggregation of small particles into larger clumps that can then settle out more easily. Disinfection, on the other hand, does not focus on solid-liquid separation but rather on eliminating pathogens from the treated water.

Therefore, sedimentation is the ideal process for effectively separating solids from liquids in the context of wastewater treatment.