Case Study: High-Color Papermaking Wastewater Decolorization Using Water Decoloring Agent

Project Background

A papermaking factory producing dyed paper products was facing serious challenges in treating its wastewater due to extremely high color intensity and elevated COD levels. The wastewater originated from paper dyeing and coating processes, containing a high concentration of residual dyes and organic compounds. Conventional inorganic coagulants alone were unable to achieve stable color removal, making it difficult to meet pretreatment requirements before further treatment or reuse.

To address this issue, a laboratory-scale jar test was conducted to evaluate the performance of a composite water decoloring agent combined with polyacrylamide for efficient color and COD reduction.

Raw Wastewater Characteristics

The wastewater showed extremely high color intensity, which is typical for papermaking effluent containing dyes and pigments.

Treatment Method and Dosage

A standard jar test was carried out using a 60 ml wastewater sample with the following treatment steps:

1. Water Decoloring Agent Addition
   A composite water decoloring agent was added at an equivalent dosage of approximately 1666 ppm, followed by rapid and uniform mixing.

2. pH Adjustment
   The pH value was adjusted to the optimal range of 7–8 using acid or alkali to enhance decolorization efficiency.

3. Flocculation Enhancement
   A diluted polyacrylamide solution was added at a dosage of 5–15 ppm to promote floc growth and improve solid–liquid separation.

4. Sedimentation
   The mixture was gently stirred and allowed to settle. Clear separation between flocs and treated water was observed within 5–10 minutes.

Treatment Results

After treatment, the wastewater quality showed a significant improvement, especially in color removal.

Performance Evaluation

• The treated wastewater color was reduced to below 80, meeting the first-stage pretreatment requirements.

• COD was significantly reduced, creating favorable conditions for subsequent biological treatment.

• The generated flocs were dense and settled quickly, resulting in low sludge volume.

• The treated effluent can be further treated by biological processes or combined with activated carbon adsorption for reuse applications.

Why Use Bluwat Water Decoloring Agent

The composite water decoloring agent demonstrated strong performance in treating high-color papermaking wastewater due to its effective charge neutralization and dye removal capability. When used together with polyacrylamide, the system achieved rapid flocculation, stable sedimentation, and reliable color reduction. This treatment approach is particularly suitable for papermaking, textile dyeing, printing, ink, and other industrial wastewater with high color and COD.

Conclusion

This case study confirms that a properly optimized water decoloring agent combined with polyacrylamide provides an efficient and economical solution for high-color papermaking wastewater. The treatment process is simple, fast, and adaptable to different wastewater conditions, making it suitable for both batch and continuous industrial applications.

Contact Us

If you are facing challenges with high-color industrial wastewater, Bluwat Chemicals can provide laboratory testing and customized treatment recommendations based on your actual wastewater conditions. Contact us to learn more about our water decoloring agent solutions.