Bleaching plants are industrial plants used to change the color and shade of materials by removing unwanted dyes, impurities or pigments. They are used in the textile industry to lighten or dye textiles, and in the paper industry to bleach paper or pulp. In the textile industry, bleaching plants are typically used to bleach cotton or other fibers to make them lighter or whiter before they are dyed. Most bleaching plants use chemical processes to remove unwanted dyes or impurities from the material. The most common chemicals used in these processes are chlorine or hydrogen peroxide. In the paper industry, bleaching plants are used to bleach paper and pulp before it is further processed. There are various processes used in the paper industry, such as chlorine bleaching, which is considered harmful to the environment and is therefore increasingly being replaced by more environmentally friendly processes such as oxygen or hydrogen peroxide bleaching. Bleaching plants can have different configurations and sizes depending on the application and the material being processed.