How to Use Polyaluminium Chloride for Effective Wastewater Treatment

2025-10-29

The Role of Polyaluminium Chloride in Wastewater Treatment

Polyaluminium Chloride (PAC) is a highly efficient inorganic coagulant widely used in industrial wastewater, domestic sewage, textile dyeing, and paper mill effluents.
With its fast flocculation, wide pH adaptability, and strong sedimentation performance, PAC is essential for achieving effective wastewater treatment in various industries.

How to Use Polyaluminium Chloride (PAC)

The effectiveness of PAC depends on dosage, solution preparation, and coagulation conditions. Proper use ensures high treatment efficiency and reduced chemical consumption.

Preparing PAC Solution

Before use, PAC should be diluted to a 5–10% solution.
Steps:

→ Fill the mixing tank with clean water.

→ Slowly add PAC powder while stirring.

→ Continue mixing until fully dissolved to prevent gel formation.

💡 Tip: Always add PAC to water, not water to PAC, to avoid clumping and ensure even dissolution.

PAC Dosage for Wastewater

The typical PAC dosage for industrial wastewater ranges from 5 to 300 ppm, depending on the water characteristics.
A jar test is essential to determine the optimal dosage, pH, and mixing time for the best treatment results.

Importance of Jar Test for PAC

A jar test replicates the coagulation-flocculation process on a small scale, helping you determine:

→ The most effective PAC dosage

→ The ideal pH range (usually 6.0–8.0)

→ Proper mixing speed and time

This step ensures better clarity, reduced chemical waste, and lower treatment costs.

Key Advantages of Using PAC

→ Achieves up to 90% turbidity removal

→ Works synergistically with PAM for stronger floc formation

→ Reduces COD and suspended solids (SS)

→ Suitable for municipal, textile, food, and paper industries

FAQ

Q1: What is the typical PAC dosage for industrial wastewater?

A1: The dosage varies widely (5–300 ppm) depending on water quality. A jar test is recommended to find the optimal PAC concentration for your wastewater.

Q2: How do I prepare a PAC solution?

A2: PAC is usually diluted to a 5–10% solution before use. Slowly add PAC to water while stirring to ensure full dissolution and prevent gel formation.

Q3: Why is a jar test important before using PAC?

A3: A jar test helps determine the most suitable PAC dosage, pH, and mixing conditions, ensuring maximum treatment efficiency and cost savings.