What are the water treatment processes

Sewage treatment generally includes the following three-level treatment: the first-level treatment is to remove stones, sand and fat, iron ions, manganese ions, grease, etc.  Secondary treatment is biological treatment, in which pollutants in sewage are degraded and converted into sludge under the action of microorganisms. Tertiary treatment is the advanced treatment of sewage, which includes the removal of nutrients and disinfection of sewage by chlorination, ultraviolet radiation or ozone technology. Depending on the treatment goals and water quality, some sewage treatment processes do not include all of the above processes.
The pure water treatment process depends on the quality of the raw water.
If the raw water is municipal tap water, the general process is
Sand filter--activated carbon filter--softening (optional)--security filter--reverse osmosis--ultraviolet disinfection--product water
If it is general surface water, it should be sterilized and flocculant should be added before entering the above process.
If it is well water, add a filter to remove iron and manganese after sand filtration.
The water is recycled and purified.
Quartz sand filtration is one of the most effective means of removing suspended solids in water, and is an important unit in advanced sewage treatment, sewage reuse and water supply treatment. Its function is to further remove the pollutants that have been flocculated in the water. It achieves the purpose of water purification through the interception, sedimentation and adsorption of the filter material.