1. The importance of sewage treatment

First of all, it needs to be recognized that sewage treatment is of great significance for protecting the ecological environment, safeguarding people's health and promoting sustainable economic and social development. Untreated sewage contains a lot of harmful substances such as organic matter, heavy metals, pathogenic microorganisms, etc. Directly discharged into rivers and lakes will not only reduce the water quality, but also cause soil pollution and even threaten the safety of groundwater. In addition, excessive nutrients in sewage will also lead to eutrophication of water body, cause algae overgrowth and further worsen water quality conditions.

2. Overview of diversified sewage treatment technologies

Facing the increasingly severe challenge of water pollution, the concept of "diversification of sewage treatment under diverse environmental protection" came into being. This concept emphasizes the flexible use of various treatment technologies such as physical method, chemical method and biological method according to the characteristics of different types of sewage in different regions to build an efficient, economical and applicable sewage treatment system.

Physical methods: such as precipitation and filtration, mainly remove suspended solid particles.

Chemical method: including coagulation, redox reaction, etc., used to eliminate specific pollutants.

Biological method: It is one of the most commonly used and low-cost methods to decompose organic matter by microbial metabolism.

3. Implementation case analysis

Taking a city as an example, according to its actual situation, the city adopted a combined process of "pretreatment+biological contact oxidation+advanced treatment" to treat domestic sewage. Specifically:

- pretreatment stage, grid and grit chamber are used to preliminarily remove large impurities;

-The biological contact oxidation section is provided with aeration devices and fillers to provide a good growth environment for aerobic bacteria and effectively degrade organic matter;

-Finally, advanced treatment measures such as activated carbon adsorption and membrane separation are taken to ensure that the effluent quality meets the national discharge standards.

4. Conclusion and prospect

To sum up, "Diversification of sewage treatment under diverse environmental protection" is a scientific, reasonable and adaptable solution, which can effectively deal with complex sewage problems. future, with the progress of science and technology and the joint efforts of all walks of life, we have reason to believe that in the near future, more innovative and efficient sewage treatment technologies and models will emerge to jointly promote mankind to a greener and healthier tomorrow.