Does polyaluminum chloride hydrolysis affect kaolin coagulation performance?

The effects of polyaluminum chloride (PACl) hydrolysis prior to coagulation on both the coagulation zone and coagulation performance of a kaolin suspension were investigated by a novel jar test named the “reversed coagulation test”.

Does PACL hydrolysis increase turbidity during charge neutralization coagulation?

Conclusions PACl hydrolysis prior to coagulation caused an increase in the optimal dosage for charge neutralization coagulation and sweep coagulation, and also induced an increase in the residual turbidity of a kaolin suspension during charge neutralization coagulation.

What is a polyaluminium chloride (PACL)?

The IPFs, such as polyaluminium chloride (PACl) and polyiron chloride (PICl), are a category of partially neutralized metal salts with significant polymeric fraction present in some circumstances.

What happens when aluminum chloride is added to water?

Once aluminum chloride is added into water,a series of aluminum species will form in situ through progressive hydrolysis. The primary aluminum species are thought to be monomeric, low polymerized and short lived, which are inclined to precipitate in the form of amorphous aluminum hydroxide, Al (OH) 3 (S) .

Does pH affect the hydrolysis of PACL?

Based on the work done by Wang et al. (2004), solution pH has a significant effect on the hydrolysis of PACl, especially for PACl with a low basicity ( [OH]/ [Al]). It was found that a large amount of Al b can form for PACl within weak acidic condition, but it transforms quickly into Al c after aging.

How does aluminum hydrolysis affect kaolin amorphous solids?

The adsorption of these kinds of aluminum hydrolysis products results in destabilization of the kaolin particles—charge neutralization. In most cases, the aluminum hydroxide amorphous solids form so rapidly (1–2s) that they are responsible for the charge neutralization of natural particles .