, According to the type of points a. C, solid PAC after drying form, easy to transport advantages, unit transportation costs increase (per ton of solid equivalent to 2-3 tons of liquid) b, low water insoluble, dissolution rate Fast, for drinking water and higher standard water treatment Most of the aluminum are suitable for sewage treatment, the price is relatively cheap advantages of liquid aluminum polychloride is not dry form, there is no dilution, loading and unloading easy to use, do not need tanker, The disadvantage is the transport needs tanker, the disadvantage is the use of dilution also need to increase the work intensity. According to the process of classification a, drum poly (co) aluminum chloride content in general, high water insoluble matter, used for sewage treatment. B, Plate and frame poly (co) aluminum chloride content is high, low water insoluble matter. For sewage treatment and drinking treatment, at COD200, spray-dried poly (co) aluminum chloride content is high