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 , .

Does pH affect the coagulation mechanism of kaolin suspension?

4. Conclusions In the conventional jar tests for the coagulation of kaolin suspension with PACl as coagulant, the pH value of the treated suspension and PACl dosages have significant effects on the coagulant mechanism of PACl.

Does alkalinity play a significant role in coagulation with aluminum salt (ALCL 3)?

It was confirmed in this study thatalkalinity could play a significant role in the coagulation with traditional aluminum salt (AlCl 3 ). Under low alkalinity condition, the turbidity removal is achieved by adsorption of soluble aluminum hydroxide species and the accompanying charge neutralization.

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.

Does alkalinity affect coagulation?

Alkalinity also plays a key role in the enhanced coagulation to remove NOM, since it tends to keep coagulation pH higher and reduce NOM removal . PACls could be less affected by alkalinity than alum, particularly those PACls with higher basicity , but the mechanisms involved in this phenomenon have not been elucidated.

Does pH affect Zeta potential of PACL precipitates in tap water without kaolin?

Effect of final pH on the formation and zeta potential of PACl precipitates in tap water without kaolin. (PACl: 54.0 mg·L − 1 as Al; water temperature: 12.5 °C). At pH 6.0, the RT during sweep coagulation is obviously higher than that during charge neutralization, and the latter is higher than that at pH 7.0–10.0.