There is no doubt that ss is reduced. The so-called BOD refers to the amount of oxygen needed to decompose organic matter in water by aerobic microorganisms. It reflects the amount of organic matter that can be biodegraded in water under aerobic conditions. If these organisms are precipitated and removed BOD will be reduced. The PAM is a high-flocculant, organic polymer flocculant floc larger particles formed between the resulting surface adsorption, use and effect is not the same, PAM is commonly used in non-ionic polymer flocculation Agent PAC is commonly used inorganic salt coagulant, is polyaluminum chloride, the requirements of the solution environment is also different, the anion in the alkaline conditions will be better results, the anion and cation conditions will be better under the addition of ions Different types, molecular weight 1.5 million -900 million, the product concentration is generally 8%. PAC role is through it or its hydrolysis products of the compressed double layer, the precipitation of particulate matter, the anion is mainly coagulation. The principle of reducing the indicators in water is the same as above. PAM is polyacrylamide, PAM now has three main types of anions, cations, anions and cations according to their different ion species, electrical neutralization, entrapment network and adsorption bridge four aspects of the role of the completed, will be able to Oxidized by the oxidant caused COD particulate matter precipitated down, thereby reducing the COD