Industrial water treatment seeks to manage four main problem areas: scaling, corrosion, microbiological activity and disposal of residual wastewater. Boilers do not have many problems with microbes as the high temperatures prevents their growth.
Industrial process water must be of an appropriate quality to ensure that products comply with required quality standards and that the manufacturing process is both efficient and controllable.
The industrial water treatment, start with purification steps, such as filters to get rid of the solids in the water, and then most common today in the industry chemicals are used to treat also the solved materials in the water. There is a long list of different kind of chemicals which can be used for such water treatment. And in most cases not just one kind of chemical is used, but a cocktail of different chemicals is used.
Scaling occurs when the chemistry and temperature conditions are such that the dissolved mineral salts in the water are caused to precipitate and form solid deposits. These can be mobile, like a fine silt, or can build up in layers on the metal surfaces of the systems. Scale is a problem because it insulates and heat exchange becomes less efficient as the scale thickens, which wastes energy. Scale also narrows pipe widths and therefore increases the energy used in pumping the water through the pipes.
Corrosion occurs when the parent metal oxidises (as iron rusts, for example) and gradually the integrity of the plant equipment is compromised. The corrosion products can cause similar problems to scale, but corrosion can also lead to leaks, which in a pressurised system can lead to catastrophic failures.