Turbidity removal from clay suspensions by use of organic polymeric flocculants

Abstract

Turbidity removal from clay suspensions by use of organic polymeric flocculants was studied by relating the change in floc size, optical density through a flocculation tank and amount of flocculant adsorbed onto suspended particles. Turbidity removal is represented by taking two regimes into consideration, i.e., the earlier period, appearing just after flocculant injection, when the flocculant adsorption rate controls the process, and the later period when a limited number of flocs named “mother flocs” control the process. The turbidity removal rates in both regimes were evaluated easily from the modified optical density variation proposed in this work and represented by two different first-order processes with respect to the modified optical density. The rate constants in both regimes were related linearly to each other, and its proportional constant depended on the condition of agitation. © 1985, The Society of Chemical Engineers, Japan. All rights reserved.