Final answer:
Wastewater goes through three main stages: primary (solid removal), secondary (bacterial decomposition), and tertiary (extra filtration and nutrient decomposition), to ensure it is safe for discharge or reuse.
Step-by-step explanation:
Stages of Wastewater Treatment
Wastewater is treated in three phases: primary treatment, secondary treatment, and tertiary treatment. During the primary treatment, wastewater is stored in a basin where solids settle to the bottom, and oil and lighter substances rise to the top, which are then removed. When moving to secondary treatment, the focus is on aerobic bacterial decomposition of the remaining organic solids. The final phase, tertiary treatment, involves further filtration to remove additional contaminants, as well as nutrient decomposition, before the water is disinfected and safely released back into the environment or reused for purposes such as irrigation.
The efficiency of the treatment process not only protects human health but also helps preserve the environment by ensuring that discharged water has minimal impact on rivers, lakes, and ecosystems. Each stage of treatment serves to progressively reduce pollutants and convert the wastewater into a form that is more environmentally benign.