Application of Polyacrylamide Flocculants in Dyeing and Printing Wastewater Treatment

The dyeing and printing industry generates a large amount of wastewater during the textile production process, which contains hard-to-degrade organic substances, heavy metal ions, and dyes, posing a threat to the environment and human health. To effectively address this issue, polyacrylamide flocculant showcases significant advantages in the treatment of dyeing and printing wastewater. This article will explore the basic properties, action mechanism, and practical application cases of polyacrylamide flocculant, revealing its important role in wastewater treatment.

Basic Properties of Polyacrylamide Flocculant

Polyacrylamide flocculant is a water-soluble polymer compound. Due to its molecular chain containing abundant amide groups, it is endowed with excellent flocculating, thickening, and dispersing properties. In the treatment of dyeing and printing wastewater, polyacrylamide flocculant can adsorb, bridge, and capture suspended solids, colloidal particles, and organic substances in the wastewater, forming larger flocs that settle quickly. This property allows polyacrylamide flocculant to significantly improve water treatment efficiency and reduce treatment costs in dyeing and printing wastewater treatment.

Mechanism of Polyacrylamide Flocculant in Dyeing and Printing Wastewater Treatment

In the treatment of dyeing and printing wastewater, the mechanism of polyacrylamide flocculant is mainly reflected in the following aspects:

Adsorption

Polyacrylamide flocculant's amide groups can effectively adsorb suspended solids, colloidal particles, and organic substances in the wastewater, thereby separating these pollutants from the wastewater.

Bridging

Due to the long molecular chain of polyacrylamide, it can form bridges between suspended solids in the wastewater, causing them to aggregate into larger flocs.

Net Capture

Polyacrylamide flocculant-formed flocs have a large specific surface area and net capture ability, capable of capturing and encapsulating fine suspended solids and organic substances in the wastewater.

Coagulation Aid

When polyacrylamide flocculant is used in combination with other flocculants, it can further improve the overall flocculation effect, accelerate sedimentation speed, and reduce sludge volume.

Application Cases of Polyacrylamide Flocculant in Dyeing and Printing Wastewater Treatment

Using Polyacrylamide Alone to Treat Dyeing and Printing Wastewater

In the wastewater treatment of a dyeing and printing enterprise, the method of using polyacrylamide flocculant alone was adopted. After removing large particles through grating, an appropriate amount of polyacrylamide flocculant was added for coagulation and sedimentation treatment, and then the water quality was further purified through filtration and other processes. Experimental results showed that this method could effectively remove suspended solids, colloidal particles, and some organic substances from the wastewater, with a COD removal rate exceeding 60%, and a color removal rate of over 90%.

Using Polyacrylamide in Combination with Other Flocculants

A research institution combined polyacrylamide flocculant with inorganic flocculants like Poly Aluminum Chloride (PAC) to further enhance the treatment effect of dyeing and printing wastewater. Experiments showed that the combined flocculant exhibited superior performance in wastewater treatment: PAC could quickly form larger flocs that precipitated, while polyacrylamide further adsorbed and encapsulated fine suspended solids and organic substances. This synergistic effect significantly improved the treatment effect, with a COD removal rate of over 80% and a color removal rate close to 100%.