The fact that the optimum proportion flocculation ratio is different when determined by the α (Dean and Webb) and ß (Ramon) procedures is pointed out. It is demonstrated that this difference is a consequence of the difference in the two methods, and that the two optima, though they may in certain cases lie near together, can never coincide. A new ratio (the ϵ ratio), intermediate between the α and ß ratios, and having theoretical advantages over both of them, is defined.

This content is only available as a PDF.