How to treat yellow phosphorus wastewater with polyacrylamide

Polyacrylamide (PAM), a water-soluble polymer, contains a certain number of polar groups in its molecular chain, which can bridge particles by adsorbing solid particles suspended in water or condense particles into larger flocs by charge neutralization, thus accelerating the sedimentation of particles in suspension, accelerating the clarification of solution and promoting the filtering effect. Polyacrylamide (PAM) is a good flocculant and settling aid, which can remove suspended particles, colloidal particles and some harmful impurities from yellow phosphorus wastewater. Its principle of action in yellow phosphorus wastewater treatment is as follows:

Bridging effect: it plays a bridging role on the suspended solids and colloids adsorbed in the yellow phosphorus wastewater, connecting colloidal particles and turning them into larger aggregates to accelerate sedimentation;

Dehydration effect: cationic polyacrylamide of polymer has stronger affinity for water, and its dissolution and hydration make colloidal particles dehydrate, lose hydration shell and aggregate;

Electric neutralization effect: Cationic polymer compound-cationic polyacrylamide is adsorbed on charged colloidal particles, which can neutralize the surface charges of dispersed phase particles, reduce the repulsive potential energy between particles, and make the sol agglomerate.

Wastewater will be produced in the production of yellow phosphorus, which contains a lot of harmful substances and cannot be directly discharged. All yellow phosphorus manufacturers use lime milk and recycle it after simple neutralization. However, because the sewage is weakly acidic, the acidic calcium phosphate salt generated by neutralization of lime milk and sewage hardly precipitates under weak acidic and neutral conditions, resulting in high suspended matter content, poor water quality and high turbidity, scaling (crystallization) on the pipeline wall, the inlet and outlet of the water pump and the impeller, which makes the pipeline diameter smaller and the water supply flow reduced, seriously affecting the normal production of yellow phosphorus, and the gray scaling (crystallization) formed on the pipeline wall is difficult to treat.