[China Aluminum Industry] Wastewater Treatment Coagulants are widely used in the wastewater treatment industry. The more common ones are polyaluminum chloride and polyacrylamide. In particular, products such as polyaluminum chloride and polyacrylamide have prominent effects on the flocculation and sedimentation rate of sewage, and are commonly used in the fields of daily-use wastewater and chemical wastewater, and industrial wastewater treatment. Polyaluminum chloride is the main material used for wastewater treatment in oil extraction; polyacrylamide is a multifunctional oilfield chemical treatment agent used as oil displacement agent in oil exploitation, water shutoff regulator, drilling fluid regulator, fracturing Liquid additive. The soil crust exists in the soil surface with the characteristics of high density, small pores, and low saturation hydraulic conductivity, which can impede the infiltration of soil moisture, increase surface runoff and hinder seed germination. Polyacrylamide can increase soil moisture content, inhibit soil crust formation, and increase water infiltration. Alkaline aluminum chloride has obvious effects on the flocculation and sedimentation of waste water in daily production; the other white polyaluminum chloride is a high-end product in water purification flocculant, belonging to food-grade polyaluminum chloride, also used in pharmaceutical and cosmetic products. The beauty industry uses raw materials or additives.