Polyacrylamide according to ionic properties can be divided into four types of nonionic, anionic, cationic and amphoteric polyacrylamide. According to the molecular weight to be divided into different specifications of molecular weight, ionicity, etc. derived from many models, in the face of the market cluttered specification system, for their own sewage system to select the best polyacrylamide model is indeed difficult, how a few strokes to deal with sewage or sludge polyacrylamide selection of common problems.