Chemical and Physical Factors in the Flocculation of Metal Plating Wastes with Polyelectrolytes.

摘要

Studies are described on the flocculation of metal plating wastes with cationic,anionic,and nonionic polyelectrolytes. Model wastes were prepared with Cr2O7(-2),Ni(+2),Cu(+2),and clay as a source of turbidity. Actual waste samples also were used. The efficiency of the treatment of these wastes with polyelectrolytes was defined in terms of the flocculation kinetics. The parameters of interest were the initial decrease in turbidity, dr/dt and the turbidity after 1hour. Other parameters that were evaluated in order to follow the flocculation process were the final particle size and the settled sludge resistivity to flow. The treatment of metal plating wastes by polyelectrolyte flocculation was compared to the treatment by reduction and precipitation methods. (Author)