Primary treatment is the first step in the wastewater treatment process. It involves the physical removal of large solids and debris from wastewater through screening and sedimentation. During this stage, wastewater flows into a settling tank, allowing heavier particles to sink to the bottom, forming sludge, while lighter materials float to the surface and are skimmed off. This process helps reduce the organic load and suspended solids in the water before it moves on to secondary treatment. By effectively removing these contaminants, primary treatment plays a crucial role in protecting the environment and improving water quality for further processing.