Sepn. of colloids from aq. medium by flotation - after treating successively with two polyelectrolytes

摘要

The process for the sepn. by flotation of organic or mineral colloids from an aq. or aq. emulsion medium comprises treating the medium before flotation successively with two polymers. The first is a polyelectrolyte of M. W. 1 to 5 x 105 having an coagulating effect and having a cationicity of 80-100%. The second is a polyelectrolyte of M. W. 1 to 6 x 106 having a flocculating effect. The process may be applied to surface water or to urban or industrial waste water. It enables a faster flotation rate and a lower volume of sludge.