1. Precipitation method: water is pretreated by natural precipitation method with large volume and low flow rate, such as sedimentation tank.
2. Coagulation method: the impurities in water and iron, aluminum, macromolecular and other coagulants are used to form large particle precipitates through flocculation and bridging, which are then removed by other equipment.
3.Filtration method: the treated water will flow through a device containing special filtration materials to intercept impurities in the water and be removed.
4. Softening method: calcium, magnesium and iron ions in water are removed by chemical agents or cation exchange resin.
5. Disinfection method: adding agents or using methods such as ultraviolet ray and ozone to eliminate microorganisms and bacteria in water.