Water treatment is, collectively, the industrial-scale process that makes water more acceptable for an end-use, which may be drinking, industry, or medicine. Water treatment should remove existing water contaminants or so reduce their concentration that their water becomes fit for its desired end-use, which may be safely returning used water to the environment. The processes involved in treating water for drinking purpose may be solids separation using physical processes such as settling and filtration, and chemical processes such as disinfection and coagulation.