Why should sewage undergo purification treatment?

    Answer: There are large amounts of pollutants in sewage varied in nature, from solid to soluble, from organic to inorganic. The most important feature of these pollutants is that they will consume a lot of dissolved oxygen in water after their access to water body. Besides, the nitrogen and phosphorus nutrients in sewage also promote the breeding of algae in large amount and consume a great deal of dissolved oxygen, causing eutrophication of water body, allowing it to become black and stinky contaminated water.

    Sewage purification treatment is to, in light of the feature of the sewage, separate the pollutants from sewage using physical, chemical or biological methods, or convert it into harmless, non-ozone-depleting inorganic substances. The process of sewage purification is also a process of energy consuming. It requires complex operation and management and costs high. That is the reason why we should form a good habit of saving water and reduce sewage discharge.