Why is polyaluminum chloride a good coagulant for water treatment?

Polyaluminum chloride (PAC) is highly effective coagulant for water treatment over conventional coagulants because of low dosage requirement, shorter flocculation time, smaller amount of sludge, high efficiency and low aluminum residual in treated water .

Does polyaluminum chloride coagulate with hydrolyzed coagulants?

Coagulation with hydrolyzing coagulants has been studied thoroughly, but the coagulation behavior of pre-hydrolyzed coagulants such as polyaluminum chloride (PACl), especially the coagulation mechanisms at various coagulant dosages and pH values of raw water, has not been systemically investigated and not been well understood , .

What is the difference between Alum and PACL coagulation?

The restabilization zone of PACl coagulation disappears at a higher final pH value than that of alum coagulation. Moreover, the charge neutralization and sweep coagulation zones of PACl are broader in the ranges of coagulant dosage (as Al) and pH value than those of alum.

Is PACL a pre-hydrolyzed coagulant?

As a pre-hydrolyzed coagulant, PACl is becoming increasingly popular in the coagulation–flocculation process.

Can PAC be used as coagulant for water treatment?

The ZPD value of PAC was also revealed that the flocculation tendency of PAC particles was very high in water, and the PAC could be used as coagulant for water treatment. Fig. 5.

Can PAC be prepared from aluminum chloride solution?

PAC can be prepared from aluminum chloride solution with the titration of various basification agents such as calcium oxide [16, 21], sodium hydroxide [, , ] and sodium aluminate .