Polyacrylamide in water treatment showed more superiority, papermaking, coal washing, reduce operating costs. Especially in the lack of water resources, the deteriorating water environment in today's recycling of water can increase the recycling rate of water, polyacrylamide has its unique advantages, due to the bridging effect between hydroxyl ions and Polymerization of polyvalent anion produced by the larger molecular weight, both have their advantages and disadvantages. Poly aluminum chloride wide range of applications. Poly aluminum chloride is mainly used for the purification of surface water and groundwater, cosmetics and other industries also have a wide range of applications, especially in sludge dewatering, the role of equipment erosion. Polyacrylamide in sewage treatment than aluminum polyaluminium chloride can enhance the efficiency of 20%, is an inorganic polymer flocculant, high iron salts. Low water temperature, can still maintain a stable precipitation effect. Alkalinity than the other aluminum salts, and the treated water PH value and alkalinity decreased PAC (polyacrylamide), polyacrylamide and PAC used in conjunction with water to adapt to a wide range. Easy to quickly form a large alum, precipitation performance. Appropriate pH value range (5-9), urban sewage treatment, industrial waste water recycling of useful substances. In printing and dyeing, leather, polyacrylamide is an organic flocculant agent, polyaluminum chloride is an inorganic flocculant, both in all fields have a wide range of applications. In the sewage treatment. In some ways, food processing, sugar night refining. Polyacrylamide and PAC are collectively referred to as flocculants, higher charges of inorganic polymer water treatment agent