Verification of the optimal kinetics behaviour during the methyl blue dye adsorption onto quaternized starch derivative

Abstract

This paper reports the adsorption of methyl blue dye onto a quaternized starch derivative (S-Quat) from an aqueous solution. The starch derivatization was achieved via the reaction between (3-chloro-2-hydroxypropyl) tri-methyl ammonium chloride (Quat-188) and maize starch in the presence of aqueous sodium hydroxide. Various instrumental characterization techniques were deployed to confirm the presence of important functional groups, crystalline structure and surface texture/morphology, which played key roles during the dye uptake. The Brunauer–Emmett–Teller (BET) surface area and pore size of the S-Quat were recorded as 41.328 ​m2. g−1 and 1.763 ​nm, respectively. The effect of solution pH, contact time and adsorbent concentration on the adsorption capacity of the S-Quat were examined via batch mode. Maximum adsorption of ∼260 ​mg/g was achieved at pH 2.0 ​and 75 ​min contact time. Furthermore, the kinetic data modelling showed that the Fractional power, Brouser–Weron–Sotolongo (BWS), and Fractal-like PFO (FPFO) models, respectively, were the top three models of best fit. Thus, the quaternized starch derivative (S-Quat) showed good dye adsorption potentials.

Keywords

• Adsorption
• Methyl blue dye
• Quaternized starch
• Kinetics modelling