Water treatment is the targeted change in water quality. It essentially comprises two groups of treatment:

• Removal of substances from the water (e.g. cleaning, disinfection / sterilization, iron removal and manganese removal, softening, desalination);
• Adding substances and setting parameters of the water (e.g. dosage, setting of pH value, dissolved ions and conductivity).

Water treatment is an essential process step in the production of drinking water for human consumption (drinking water supply).

The water treatment is also used for the purification of waste water, especially for the recovery (recycling) of z. B. Metals (including precious metals) from wastewater.