Is polyaluminum chloride acidic or alkaline?

Is Polyaluminum Chloride acidic or alkaline?

I. Acidic nature of polyaluminum chloride

Polyaluminum Chloride (Pac) is an inorganic polymer with a core chemical structure of poly-nuclear hydroxyl complexes (general formula: [Al₂(OH)ₙCl₆₋ₙ]ₘ). When dissolved in water, aluminum ions (Al³⁺) undergo hydrolysis reactions, releasing hydrogen ions (H⁺) that create an acidic solution with a pH value stabilized between 2.0–4.5. This characteristic gives PAC the following advantages:

• Strong electric neutralization capacity: acid environment enhances the charge neutralization effect of PAC on colloidal particles in water, and rapidly destroys the stability of suspended matter;
• Broad spectrum adaptability: high activity in the range from acid to neutral, no additional pH adjustment is required to cope with complex water quality.

Common Misconceptions Clarified: Although it is often called "alkaline aluminum chloride", PAC is not an alkaline substance. The name comes from the alkali reaction in its preparation, not the properties of the solution.

II. Four application advantages driven by acid characteristics

Efficient flocculation and sedimentation

The hydroxide colloidal aluminum hydroxide generated by PAC hydrolysis under acidic conditions can quickly capture small suspended matter through bridge adsorption and form dense alum flowers. The sedimentation speed is more than 30% faster than that of traditional coagulants (such as aluminum sulfate).

Deep removal of heavy metals and pollutants

Acid environment strengthens the complexing ability of PAC to lead, chromium, arsenic and other heavy metal ions, and improves the adsorption efficiency of dissolved organic matter (COD/BOD) and pigment, which is especially suitable for printing and dyeing, electroplating, chemical wasteWater Treatment.

Bidirectional adjustment of acid and alkali wastewater

PAC has the unique ability to "use acid to control alkali":

• • Alkaline wastewater: directly neutralize OH⁻ ions, reduce alkalinity and flocculate pollutants;
  • Acidic wastewater: H⁺ is consumed through hydrolysis to buffer pH fluctuations and avoid secondary medication.

Cost and operation optimization

• • The dosage of the injection is reduced by 40% compared with the traditional agent (the same turbidity removal rate);
  • No need to adjust pH value in advance, simplify the process flow, reduce labor and equipment costs.

III. PAC solutions that match scenarios

For different water quality needs, the following product lines are recommended:

IV. Acid value conversion case of PAC

• Wastewater treatment of papermaking plant: in the alkaline wastewater with pH 11.5, the turbidity removal rate reaches 98% after PAC addition, saving 35% of neutralizer cost;
• Comprehensive wastewater in electroplating park: Acidic chromium-containing wastewater (pH 3.0) was treated by PAC, and the chromium ion retention rate was more than 99.5%, reaching the standard discharge.

Choose us —— Aierfuke

✅ Purity assurance: spray drying process is adopted, aluminum content is more than 29.5%, salt base degree is precise and controllable (40-90%);

✅ Customized services: free water quality testing, pH matching scheme and optimization of dosage parameters;

✅ Resource support: The technical team responds 24 hours a day to provide pilot scale and effect verification of the agent.

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