Cationic starch intercalated montmorillonite nanocomposites as natural based adsorbent for dye removal

Cationic starch intercalated montmorillonite (Mt-CST) adsorbent was developed for the removal of basic dyes, namely, Basic Blue (BB66) and Basic Yellow (BY1) from aqueous solution. Cationic starches (CST) containing ammonium groups with the degree of substitution of 0.16 (CST1) and 0.69 (CST2) were successfully prepared from the reaction of low molar mass starch with (3-chloro-2-hydroxypropyl trimethyl) ammonium chloride. A series of Mt-CST nanocomposites were prepared by controlling the mass ratios of Mt:CST. Adsorption of BB66 and BY1 from aqueous solution onto Mt-CST was studied. The adsorption capacity increased with decreasing of cationic groups in the CST or increasing the mass ratios of Mt:CST. The results showed that the Mt-CST11 nanocomposite with the mass ratio of Mt:CST1 of 69: 31 exhibited relatively high adsorption capacities for basic dyes. The results of adsorption behaviors of BY1 on Mt-CST11 and Mt-CST21 indicated that the adsorption processes followed well the Langmuir isotherm.