Primary treatment
is the first stage of wastewater treatment in a wastewater treatment plant. It is an important step in the process of treating wastewater, as it removes large solids and suspended matter from the water. Primary treatment typically involves physical processes such as screening, sedimentation, and flotation.
- Screening: Screening is the first step in primary treatment. It involves passing wastewater through a screen to remove large objects such as rags, sticks, and other debris that could clog or damage downstream equipment.
- Sedimentation: Sedimentation is the process of allowing suspended solids to settle out of the wastewater by gravity. This process can be done in a sedimentation tank or clarifier. The settled solids are then removed from the bottom of the tank and disposed of properly.
- Flotation: Flotation is a process that uses air bubbles to separate suspended solids from wastewater. The air bubbles attach to particles in the water, causing them to float to the surface where they can be skimmed off and removed from the water.
Primary treatment is important because it removes large solids and suspended matter from wastewater before it enters secondary treatment processes such as biological treatment or chemical precipitation. This helps reduce wear and tear on downstream equipment and improves overall efficiency of the plant.