Previously, PAM was added to electroplating wastewater to facilitate sludge precipitation; now, ferric chloride is added first, followed by PAM, and then the sludge settles and floats to the surface. Why is that?
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Previously, PAM was added to electroplating wastewater to facilitate sludge precipitation; now, ferric chloride is added first, followed by PAM, and then the sludge settles and floats to the surface. Why is that?
There are generally just a few reasons why sludge floats to the surface. 1. Excessive amount of PAM added. Second, the wastewater contains substances that release gases easily upon decomposition; these gases form tiny bubbles that cause the sludge to float to the surface. Third, excessively high concentrations in the pretreatment wastewater can also cause sludge to float to the surface.
It is estimated that the dosage of the chemical was too high; generally, PAC+PAM is used for coagulation and sedimentation in electroplating wastewater.
Take some water, stir it to break the bubbles, and see if it will sink