Adsorbates
All reagents used are of analytical grade from Merck (Germany).
Stock solutions (1 g L1
) of both the dyes methylene blue (MB) and
eosin yellow (EY) were prepared by dissolving appropriate
quantity of MB (cationic dye) of chemical formulae C16H18ClN3S
(MW= 319.87 g mol1
) and EY (anionic dye) of chemical formulae
C20H6Br4Na2O5 (MW= 691.88 g mol1
) in distilled water. All test
solutions of the desired concentrations were prepared by
successive dilutions to get the required initial experimental
concentration (100–400 mg L1
). The structures of both the dyes
are represented in Fig. 1.