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 optimal pH range for Pac coagulation?

The optimal pH range for PAC coagulation performance was 7.5 to 8.0. The coagulation process in conventional water treatment could be enhanced and the ensuing water pH decline reduced appreciably by applying the right dosage of polyaluminium chloride and appropriate process conditions of pH, fluid mixing speed matrix and residence time.

Is polyaluminium chloride better than polyelectrolyte – alum-based coagulation?

At the Barekese Water Treatment Plant in Ghana, an alternative, the polyelectrolyte – polyaluminium chloride (PAC) is also used in coagulation but limited information is available on the operating conditions required to achieve better performance than alum-based coagulation.

Which coagulant is better PAC or pac-18?

Wastewater (tertiary) treatment for coagulant doses of 10 –100 mg Al/L. The initial characteristics of coagulation performance of the tested coagulants. lower turbidity values below 1 NTU. PAC exhibits better performance, than PAC-18. For all coagulant doses the with only the exception of 10 mg Al/L dose.

How PACL coagulation zones are compared with alum?

The coagulation zones at various PACl dosages and solution pH values were developed and compared with those of alum. It is found that the optimal mechanism under acidic condition is charge neutralization, while alkaline condition will facilitate the coagulation of PACl.

Is PACL a pre-hydrolyzed coagulant?

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