How to find The Right PAC dose for wastewater treatment?

Adding too much poly aluminum chloride (PAC) increases costs. Adding too little reduces treatment efficiency. The right dose depends on COD, TSS, PH and turbidity. Here is how to find it:

Understand the waste water first:

COD (mg/L): measures organic and inorganic pollutions.

TSS (mg/L): measures suspended solids in water.

pH: PAC works best between 5-9.

Turbidity: high turbidity often means a higher PAC dose is needed.

Calculate a JAR test: this is the most accurate way to determine the PAC dose.

Steps:

Take wastewater samples in separate jars.

Add different PAC doses (10-20-30 mg/L, etc.).

Mix rapidly (100-150 rpm) for 1-2 minutes.

Reduce mixing (20-40 rpm) for 10-15 minutes.

Let the jar settle for 20-30 minutes.

Measure COD, TSS, and turbidity in the supernatant.

Choose the dose that gives the lowest COD, TSS and turbidity.

Factors that affect PAC Dose:

Wastewater composition: higher organic loads need more PAC.

pH: adjust between 5-9 for best results.

Temperature: cold water may need a higher dose.

Mixing: poor mixing leads to incomplete treatment.

Monitor and adjust regularly:

Wastewater changes over time. Keep checking COD, TSS and turbidity. Adjust PAC doses as needed. A well-optimized PAC dose cuts costs and improves treatment. Run a jar test before doing blindly.