Welcome to view our artical about the PVA waste water treatment.Today is the second part of the Physical law method.

Physical law-2:Salting gel method/Membrane separation method

1.4, Salting gel method

In the PVA wastewater treatment process, salting gel method can be used. That is, according to the characteristics of PVA, the salting-out agent sodium sulfate and the gelling agent borax are added into the waste water so that the borax reacts with the PVA molecules to form the PVA-borax diol type structure. Under the action of Na + and SO42-, Through its powerful water and ability to absorb a large amount of water around, making PVA dehydration from the precipitation of waste water.

The results showed that the dosage of sodium sulfate and borax were 14g / L and 1.4g / L respectively when the concentration of PVA in wastewater was 12g / L, and the reaction time was controlled for 20min , The reaction temperature is 50 ℃, the initial pH of the solution is 8.5 ~ 9.5, the recovery rate of PVA is more than 90%.

Polyvinyl alcohol in textile printing and dyeing desizing wastewater was treated and recovered by chemical coagulation method. PVA and PVA recovery rate and COD removal rate in the productive scale recovery wastewater were all successfully reached about 80%.

Study on the Recovery of PVA in Desizing Wastewater by Condensation. The results showed that the recovery rate of PVA batch reaction was up to 90%. On this basis, the PVA continuous recovery process was achieved with the recovery rate of 80%.