Effect of different polyaluminum chloride content on wastewater treatment There are many influencing factors in the process of coagulation, such as water temperature, pH value, water conservancy conditions, input amount, etc. Among them, pH value has the most obvious influence on coagulation effect. Different pH value coagulant hydrolyzate have obvious differences, a direct impact on the treatment effect. The coagulant made of polyaluminum chloride will continuously produce H + during the hydrolysis, which requires that there must be enough alkali in the water to neutralize the H +. In addition, the amount of input also has a direct impact on the treatment effect, if the input is insufficient, the suspended solids in water is not fully destabilization, it will directly affect the settlement and separation, resulting in reduced treatment efficiency, excessive input, can lead to ultra-granular Dutch in an unstable state, will also affect the treatment effect. Polyaluminum chloride is a kind of high-performance non-polar polymer flocculant with the molecular formula of A1n (OH) mC13n-mo. Compared with other inorganic polymers, polyaluminum chloride has the advantages of stable molecular structure, large flocs, Fast, low cost, good coagulation effect and other advantages, is a good method of sewage treatment, mainly for domestic sewage and industrial wastewater treatment.