Pickling is usually associated with passivation. Generally speaking, the materials that need pickling must be passivated, because after pickling, the surface will not form a passive film, or the thickness of the passive film is very thin, so there is no effect. The subsequent passivation process should be added to form and change the passivation film on the surface. The typical waste liquor of polyacrylamide pickling is generally composed of nitrate, Fu compound, trivalent iron ion, trivalent chromium ion, and nickel ion. Because there are many pollution sources, it is difficult to control.
The pickling waste liquid is filtered by the grid and then immersed in a homogenization tank. The water quality and quantity of pickling waste liquid are kept in a relatively stable range to ensure the normal operation of subsequent neutralization and sedimentation system.
In the next step, the pickling waste liquid enters the polyacrylamide neutralization reaction tank, and lime is added to adjust the pH value. In order to remove Fu ions from wastewater, the pH value of the neutralization tank should be controlled above 10.5. When the pH value reached 9.5, the heavy metal ions formed hydroxide precipitation, and CaF2 and f precipitated together.
Due to the excessive addition of lime, the insoluble part directly forms sludge, and the dissolved calcium ion will combine with sulfate ion in wastewater to form a large amount of calcium sulfate. PAM polyacrylamide is added to accelerate the sedimentation and coagulation, and then the neutralized and precipitated pickling waste liquid enters the sedimentation tank for solid-liquid separation. The clear liquid is discharged through the sedimentation tank, and the sediment enters the sludge storage tank for dehydration to form sludge cake.
Oubo Chemical is one of the biggest Polyacrylamide manufacturers in China, Oubo specializes in supplying Cationic Polyacrylamide, Anionic Polyacrylamide, and Nonionic Polyacrylamide, we have advanced equipment and professional staff, which ensure all the products and service to be in good order. The annual capacity of polyacrylamide has broken through 50,000 ions in 2018, and the quality management system of Oubo has been certified by IS09001:2008. We proudly stand behind our product.
Post time: Jan-29-2021