Q. What are the 3 stages of sewage treatment plant?

Primary treatment (anerobic process): This process helps solids settle at the bottom with oil grease & lighter solids a floating on the surface and discharges remaining liquid for secondary treatment process. Secondary treatment (aerobic process): The discharged liquid is treated with water-borne aerobic micro-organisms and indigenous to remove suspended and dissolved solidsTertiary treatment: The final cleaning process involves removal of inorganic substances and compounds (phosphorus and nitrogen) to enhance the quality of the water before it is discharged to the environment recycled or reused.