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 .

Can polyaluminum chloride be used in water treatment?

In this study, synthesis and speciation of polyaluminum chloride (PAC) for application in water treatment was investigated using a colorimetric speciation method. It was possible to produce stable preparations of PAC solutions in which a relatively stable cationic polymer predominated.

What is high-purity poly-aluminum chloride (PACL)?

Poly-aluminum chloride (PACl) is one of the common coagulants for water and wastewater treatment. A new Chinese national standard of PACl has been implemented, where the concentration of insoluble substances, iron and heavy metals is to be controlled strictly, then researches on the preparation of high-purity PACl are needed.

What is the molecular formula of poly-aluminum chloride?

One of the major pre-polymerized coagulants, poly-aluminum chloride (PACl) is used broadly for water and wastewater treatment. PACl contains different amounts of hydroxyl, and the molecular formula of PACl is [Al m (OH) n (H 2 O) x]·Cl 3m−n (n ≤ 3 m).

Can a cationic polymer predominate PAC solution?

It was possible to produce stable preparations of PAC solutions in which a relatively stable cationic polymer predominated. The mode of preparation has a dramatic effect on the composition of PAC preparation.

What is the difference between high-purity PACL and conventional PACL?

The preparation process of high-purity PACl and conventional PACl is different as stated previously, where raw materials used and the operating conditions are different. As shown in Table 5, Al (OH) 3 is relatively expensive than bauxite but sulfydryl/PAM polymer is cheaper.