Fig. 6 shows
that the percentage dye extracted decreases from 100% to
78% as the initial concentration increases from 30 to
100 mg/l. The decrease in extraction with increase initial dye
concentration can be explained by the fact that at higher dye
concentration, the limited extractant in the solution cannot
react with the excess dye [42]. The decrease in percentage dye
removal with increasing initial dye concentration may be
attributed to the tendency of dye molecules to associate and
form aggregates of low diffusivity with increasing initial dye
concentration [43], and this reduces the rate of dye extraction
which is a diffusion controlled process.