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 basicity of high-purity PACL?

The basicity of high-purity PACl can be maintained at about 92% after the adjustment by calcium aluminate (Table 3), it has exceeded the national and international standards of PACl.

Does high-purity PACL remove turbidity?

The results demonstrate that for the whole dose range studied, high-purity PACls removed more turbidity than conventional PACl. On the other hand, when the dose was greater than 4 mg L −1 as Al, the high-purity PACl showed great UV 254 -absorbance removal capacity; which was even much greater at high does (e.g., 10 mg L −1).

Why does high-purity PACL have a high zeta potential?

On the other hand, when the dose was greater than 4 mg L −1 as Al, the high-purity PACl showed great UV 254 -absorbance removal capacity; which was even much greater at high does (e.g., 10 mg L −1). This could be partly attributed to the charge effect where a relative high zeta potential in the test water was achieved by dosing high-purity PACl.

Are pre-polymerized aluminum salts a good coagulant for water treatment?

Although the pre-polymerized aluminum salts (PACl) show better coagulation performance in some cases in comparison with conventional coagulants , their applications in water treatment are still limited due to the high cost of raw materials . Therefore, it is urgently required to develop more cost-effective coagulants for water treatment.

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).