Application of PAM in sewage treatment

Polyacrylamide is a widely used chemicaladditive, it can treat many types of sewage.For the following types of sewage,the correct use of polyacrylamide can achieve a very good water purificationeffect.

1. Papermaking sewage.

In general, the organic concentration inthe sewage generated by papermaking sewage is relatively high and the watercontains a large amount of suspended substances, so its treatment is mainly totreat the chroma in the sewage and reduce or remove cod. In this way, we candirectly use the flocculation precipitation process, using anionicpolyacrylamide and PAC (polyaluminum chloride) mixed and used, so that most ofthe color can be removed, and most of the insoluble COD and part Soluble CODand BOD5 are removed to achieve a better treatment effect.

2. Printing and dyeing sewage.

The key to the coagulation treatment ofprinting and dyeing wastewater is to choose the appropriate flocculant. Theconventional flocculants suitable for the treatment of printing and dyeingwastewater mainly include aluminum sulfate, ferric sulfate, and ferric chloridein the early stage, and cationic polyacrylamide in the later stage. Thetreatment of some water-insoluble dye wastewater is obvious. For example, theremoval rate of disperse dye, vat dye, sulfur dye, COD and chroma are veryhigh.

3. Sewage from slaughterhouse.

Slaughterhouse wastewater treatment usescationic polyacrylamide in combination with other water treatment agents,biological methods, membrane methods and other methods, by adding Jianghepolyacrylamide flocculant to promote sludge solid-liquid separation inslaughterhouse wastewater, and can be effective The organic matter is fused andremoved on site to reduce the pollution load in a short time. It can not onlyremove the COD, BOD, SS and ammonia nitrogen content in the wastewater, butalso decolorize the wastewater and make the organic matter flocculate andprecipitate, reducing the slaughterhouse. The harm of meat product wastewaterto the environment. Reduce the probability of eutrophication of surroundingwater bodies, maintain the self-purification ability of water bodies, ensurethe safety of environmental water bodies and the sanitation of agriculturalirrigation water quality. The process is simple, and the medicine can be adjustedaccording to the change of water quality, which has a certain effect ondeodorization, and has become the main method of water treatment in manyslaughterhouses.

4. Coal washing sewage.

Polyacrylamide for coal washingwastewater is a more professional polyacrylamide. Polyacrylamide for coalwashing wastewater has better precipitation effect than general polyacrylamide.The coal extracted from coal mining with polyacrylamide for coal washingwastewater usually contains some impurities. The separation efficiency of coaland impurities can be improved by adding a flotation agent. The fine coalfloats out and the tail coal settles. The clean coal in the tail coal is thenrecovered by sedimentation, filtration or centrifugation. Polyacrylamide isused in the sedimentation process, and polyacrylamide is used for coal washingwastewater to promote solid-liquid separation. It is then sent to theconcentrator, where the clean water is recovered from the overflow of theconcentrator and recycled. The powdered clean coal is recovered by filtrationand centrifugation. Polyacrylamide is added again during filtration andcentrifugation to improve the separation efficiency.

5. Domestic sewage.