Clarification is an essential step in the wastewater treatment process to remove the solids through gravity settling for providing a clarified and clean liquid. These are also used to remove the materials like oil, grease, solids etc. A clarifier is generally divided into two types: 1. Primary Clarifier: These clarifiers are used to separate the settleable solids from the incoming raw wastewater. They are located the downstream of plant’s screening process. This whole process is known as primary clarification, also known as sedimentation. 2. Secondary Clarifier: These clarifiers are located downstream of biological treatment. Their primary purpose is to separate the treated wastewater from the natural mass. Its main goal is to return the activated sludge. The whole process is known as secondary clarification.