Water treatment is widely used in industrial water, municipal/drinking water treatment, sewage wastewater treatment and seawater desalination.

In the field of industrial water, it is mainly applied to industrial circulating water treatment and industrial boiler water treatment. The agents used in industrial circulating water treatment are mainly scale inhibitors, corrosion inhibitors, algaecides, cleaning agents, pre-film agents, etc. The common methods of industrial boiler water treatment include outside pot water treatment and inside pot water treatment, and the agents used are mainly: corrosion and scale inhibitors, deaerators, feed water alkali reduction agents, ion exchange agents, regenerating agents, softeners, alkalinity regulators, scale removers, etc.

Municipal / drinking water treatment involves water treatment agents in general: algaecide, flocculant, corrosion inhibitor, etc.

The water treatment agents involved in sewage treatment are generally flocculants, sludge dewatering agents, defoamers, chelating agents, decolorizers, etc.

The mainstream technologies for desalination include distillation and membrane methods. Membranes are easily clogged in application, so it is necessary to add scale inhibitor and retarder, detergent, flocculant, scale inhibitor and dispersant to the water. The distillation method is easy to produce pot scale and thus reduce the evaporation efficiency, so the water can be softened by adding polyphosphate, organic phosphoric acid, phosphonate polycarboxylic acid, etc. to the raw water to chelate calcium, magnesium ions and other metal ions to make them less likely to precipitate and prevent the formation of scale.