Adsorption refers to the process by which one substance attaches to the surface of another substance. Specifically, adsorption uses the surface of porous materials to attract and fix pollutants in water on its surface, thereby separating these pollutants from the water body.

Sewage treatment plants mainly treat seriously polluted domestic sewage and industrial wastewater, with complex processes and large environmental impacts, while gray water treatment plants focus on treating less polluted gray water, with relatively simple processes and small environmental impacts.

At present, the coagulants used in the market are mainly divided into three categories: inorganic coagulants, organic coagulants and polymer coagulants. Each type of coagulant has its own unique chemical properties and application scenarios.

Ultraviolet disinfection technology is widely used in water treatment, mainly including drinking water treatment, sewage treatment, industrial wastewater treatment, aquaculture and swimming pool disinfection.

The main types of water treatment plants are: 1. Drinking water treatment plants, 2. Sewage treatment plants, 3. Industrial water treatment plants, 4. Seawater desalination plants.

The prices of aluminium sulfate (alum) and polyaluminium chloride are relatively low and suitable for large-scale applications. Although polyacrylamide (PAM) has a good flocculation effect, it is more expensive and is suitable for scenarios with high requirements for flocculation effect volume.