Poly aluminum chloride due to different levels of content is also different due to different levels of different levels of PAC. Polyaluminium chloride PAC is widely used in various types of sewage treatment, such as: printing and dyeing wastewater treatment, coal mine sewage treatment, mineral processing sewage treatment, papermaking sewage treatment, aquaculture wastewater treatment, chemical industry sewage treatment, has become the most commonly used water treatment Pharmacy. However, many users are still unable to use the PAC properly, in particular, they can not make the best performance of the PAC PAC, leading to excessive consumption and waste in the use of the PAC. The amount of sewage treatment input varies, but only after rigorous testing. We can get precise dosage. In the small test, we should follow the following basic principles: the dissolved PAC PAC should be controlled at 5% -10%, PAC content by different levels are different, the higher the content, the lower the proportion of its dissolution. Polyaluminum chloride solution will be added to the sewage, should follow the principle from less to more, dosage increase from one-thousandth, in order to achieve the best water treatment effect. Do not overdose, or increase the cost of sewage treatment. Polyaluminum chloride in different water quality dosage in a low turbidity water, the ratio of water and polyaluminum chloride in accordance with the general 4: 1 dosing, then add tap water dilution, and stirring until completely dissolved. Second, in domestic sewage, refer to per ton of sewage first cast about 30Kg of PAC products. If used with polyacrylamide products will be better. Third, in the industrial sewage treatment, the proportion of low turbidity water injection ratio configuration, try to use high content of PAC products. The solubility of polyaluminum chloride refers to the polyaluminum chloride into the water after a few percent can melt away. The polyaluminum chloride used for potable water treatment has a solubility of 99.7%, that is to say 0.3% water-insoluble. Polymeric aluminum chloride for industrial wastewater treatment has a solubility of 98%, ie 2% insolubles.