Last time, we talked about the PAM is normally applied in wastewater treatment in the tertiary step. But somebody would say it’s dangerous to use PAM, many chemicals or poison elements will be left in the wastewater and it’s no good.————————-My dear friends, it’s just the pre-treatment, later you may need to use membrane facilities to clean the water for daily use.
Introduction to Polyacrylamide
Polyacrylamide (PAM) is a linear polymer with the chemical formula (C3H5NO)n and a molecular weight typically between 1×107. It is a hard, glassy solid at room temperature, and its products include gels, latexes, white powders, translucent beads, and flakes. Polyacrylamide has excellent thermal stability and water solubility, dissolving in water in any proportion to form a uniform, transparent liquid. Furthermore, polyacrylamide exhibits excellent flocculation properties, reducing frictional resistance between liquids. It is widely used in industries such as oil extraction, water treatment, textiles, papermaking, mineral processing, pharmaceuticals, and agriculture, earning it the reputation of a “multi-industry additive.”
Polyacrylamide Wastewater Treatment Process
Based on the characteristics of polyacrylamide wastewater, the treatment process typically includes the following steps:
1, Pretreatment:
Screens, regulating tanks, and other facilities are used to remove large particles and suspended solids from the wastewater to regulate water quality and quantity.
2, Coagulation and Sedimentation:
Adding a coagulant (such as polyacrylamide itself or another coagulant) causes fine particles and organic matter in the wastewater to rapidly aggregate into larger particles, forming flocculent sediments. This step effectively reduces the concentration of suspended solids and the organic matter content in the wastewater.
3, Biological Treatment:
Aerobic or anaerobic biological treatment techniques are used to utilize the metabolic activity of microorganisms to degrade organic matter in the wastewater. For polyacrylamide wastewater, more efficient biological treatment processes such as biofilm reactors and sequencing batch sludge (SBR) may be required.
4, Advanced Treatment:
Depending on the effluent quality requirements, advanced treatment technologies such as activated carbon adsorption, membrane filtration (such as ultrafiltration and reverse osmosis), and ozone oxidation can be selected to further remove pollutants such as organic matter, color, and heavy metals from the wastewater.
5, Disinfection and Discharge:
Finally, chlorination, ultraviolet disinfection, and other methods are used to kill microorganisms in the wastewater, ensuring that the effluent meets discharge standards before discharge.
Polyacrylamide Wastewater Treatment Case Study
A chemical plant generates a large amount of wastewater during the production of polyacrylamide. This wastewater contains high concentrations of organic matter and suspended solids and is difficult to degrade. To treat this wastewater, the plant adopted the following treatment process:
1. Pretreatment Stage:
The wastewater first passes through a screen to remove large impurities and then enters a regulating tank for homogenization and flow balance.
2. Coagulation and Sedimentation Stage:
In the coagulation and sedimentation tank, an appropriate amount of polyacrylamide is added as a coagulant to rapidly aggregate fine particles and organic matter in the wastewater into larger particles, forming flocculent sediments. Solid-liquid separation is achieved in the sedimentation tank, effectively reducing the concentration of suspended solids and the organic content in the wastewater.
3. Biological Treatment Stage:
After coagulation and sedimentation, the wastewater enters a bioreactor for aerobic biological treatment. In the bioreactor, microorganisms use oxygen as an electron acceptor to degrade organic matter in the wastewater into harmless substances such as carbon dioxide and water.
4. Advanced Treatment Stage:
To further remove pollutants such as organic matter and color from the wastewater, the chemical plant uses activated carbon adsorption and membrane filtration technologies. Activated carbon adsorption removes organic pollutants and color from the wastewater; membrane filtration further removes suspended solids, bacteria, viruses, and other microorganisms.
5. Disinfection and Discharge Stage:
Finally, the disinfected wastewater meets discharge standards and can be directly discharged or reused in other production processes.
After the above treatment processes, the chemical plant’s polyacrylamide wastewater has been effectively treated, and the effluent quality meets relevant national discharge standards. Furthermore, this treatment process achieves resource utilization of wastewater, saving water resources and treatment costs for the enterprise.
In summary, polyacrylamide, as an important polymer, is widely used in various industries. However, the wastewater generated during its production process causes certain environmental pollution. Through scientific wastewater treatment processes and technical means, pollutants in polyacrylamide wastewater can be effectively removed, protecting the ecological environment and achieving sustainable development for the enterprise.
