With the rapid development of society, industrialization and urbanization, the problem of water pollution has become increasingly serious, which has become one of the key factors restricting sustainable development. In this context, sewage treatment as an important part of environmental protection, its importance is self-evident. This paper aims to explore the essence of sewage treatment and its significance to environmental protection.

First, the concept and purpose of sewage treatment

Sewage treatment refers to the process of removing pollutants from water by physical, chemical or biological methods, so that the water quality reaches a certain standard and then discharged into the natural environment or recycled. Its main purpose is to reduce water pollution, protect human health and ecological environment, and realize the effective utilization of water resources.

Second, the importance of sewage treatment

1. Improve water quality: By effectively treating sewage, the content of harmful substances such as organic matter and heavy metals in water can be significantly reduced and the water quality can be improved.

2. Protect the ecological balance: untreated sewage discharged directly will destroy the aquatic ecosystem and affect the survival of animals and plants. Reasonable sewage treatment measures are helpful to maintain the stability and diversity of the ecosystem.

3. Promote resource recycling: Modern sewage treatment technology can not only purify water quality, but also recover valuable resources such as phosphorus and nitrogen from wastewater, thus achieving the goal of waste reduction and recycling.

4. Ensuring public health: Clean and safe drinking water is the cornerstone of people's health. Effective sewage treatment can prevent the spread of pathogenic microorganisms and reduce the incidence of water-borne diseases.

Third, the technical means of sewage treatment

Primary treatment: it mainly includes the initial purification process of intercepting large particles of impurities by grid and removing suspended solids by sedimentation tank.

Secondary treatment (biological treatment): the dissolved organic matter is decomposed by microorganisms by activated sludge method and biofilm method.

Tertiary treatment: For specific occasions with high requirements, advanced treatment is needed, such as reverse osmosis, ultrafiltration and other advanced oxidation technologies to further remove residual pollutants.

IV. Conclusion

In a word, sewage treatment is a complex but extremely important work, which is not only the key way to solve the current environmental pollution problem, but also an indispensable part to promote green and low-carbon development and build an ecological and civilized society. future, with the progress of science and technology and the improvement of social consciousness, we have reason to believe that sewage treatment will become more efficient, economical and environmentally friendly. This is not only related to the health of Mother Earth, but also to everyone's quality of life and the bright future of future generations.