Polyaluminum chloride (PAC) is a commonly used flocculant widely used in the field of sewage treatment. Its main functions in sewage treatment include:
Flocculation: Polyaluminum chloride forms hydroxide ions in water, which react chemically with suspended and colloidal particles in the water to form larger flocs. These flocculents become heavier in water and are prone to settling or being filtered, effectively removing turbidity and suspended solids from the water.
Precipitation effect: The addition of polyaluminum chloride can promote the precipitation of some soluble ions in water, such as phosphate and alkaline metal ions. This helps to reduce nutrients in water and prevent eutrophication issues, especially when dealing with some organic wastewater in wastewater.
Adjusting water quality: PAC can also adjust the pH value of water to a suitable range, which is helpful for other water treatment processes. By controlling water quality, the effectiveness of subsequent treatment steps can be improved.
Bactericidal effect: The chloride ions in polyaluminum chloride have a certain bactericidal effect, which helps to remove microorganisms in water and reduce environmental pollution.
It should be noted that the dosage of polyaluminum chloride needs to be carefully controlled during use to prevent residual substances from having adverse effects on water bodies. In addition, different types and concentrations of wastewater may require different types and dosages of polyaluminum chloride, so adjustments should be made according to specific situations in practical applications.