Polyaluminum chloride is an inorganic polymer flocculant, referred to as pac, is a complex of aluminum hydroxide and aluminum chloride. Polyaluminum chloride hydroxide ions have a bridging effect, while polyvalent anions can also produce polymerization, polyaluminum chloride and therefore has a strong role in the neutralization of colloidal substances, the hydrolyzate of suspended solids in the water excellent shelf Bridge adsorption, the selective adsorption of dissolved substances. In the use of polyaluminum chloride, the need to pay attention to its best dosage. According to the different conditions of raw water, first try to get the best dose. Dosing by the best dosage to vote, and pay attention to the operation of the adjustment, such as see the settling pond alum less, large turbidity, the dosage is too small; see the precipitation alum large and up , Yu Zhuo high, the dosage is too large, should be properly adjusted. Polyaluminum chloride dosage can be determined by calculation. Different turbidity polluting aluminum chloride dosage varies, different levels of pac dosage also vary. Under the same water quality conditions, the content of PAC is from 25% to 35%, the content is from low to high, dosage is also gradually reduced. Generally low turbidity water, polyaluminum chloride in accordance with the ratio of 1: 3 dissolved in water, plus 10-30 times diluted with water to the desired concentration before use. In the process of domestic sewage treatment, per ton of sewage first cast about 30g of pac. Then dosing diluted polyacrylamide pam, if the effect is not obvious, please reduce or increase pac dosage as appropriate. In short, the specific use of inorganic flocculant aluminum PAC need to be based on the situation of the sewage and the treatment process to choose