Since the first use of aluminum sulfate in feedwater treatment and patents in the United States at the end of the 19th century, aluminum sulfate has been widely used for excellent coagulation sedimentation performance. Aluminum sulfate is currently the most used flocculant in the world, with an annual output of about 5 million tons of aluminum sulfate, nearly half of which is used in water treatment. Commercially available aluminum sulfate has two forms of solid and liquid, and the solid is divided into two types according to the content of insoluble matter. The solid product which is commonly used in drinking water purification in China is a complex of aluminum sulfate and potassium sulfate. Salt, but not much in industrial water and wastewater treatment.