Highly efficient adsorbent material for removal of methylene blue dye based on functionalized polyacrylonitrile

Abstract

Considerable interest has been allocated for developing novel materials as adsorbents to be used in wastewater treatment. In the current work, aminated polyacrylonitrile (AMPAN) was prepared, and the amino functionalities were further modified into ammonium salts. The polymer was combined with montmorillonite forming QPAN/MMT composite. AMPAN was also modified with a reaction with Maleic anhydride to get carboxylated polyacrylonitrile (CPAN). The structure of the modified polymers was elucidated using techniques such as XRD, FT-IR, TGA, SEM, EDX and elemental analysis. PAN derivatives were tested for removal of methylene blue dye (MB) from aqueous solutions. Different parameters such as adsorbent dose, initial dye concentration, contact time, pH and temperature were studied to obtain the optimum. The removal percentage of MB dye using 0.1 g QPAN/MMT at optimum pH = 8 was 99.7% after 20 min. The rate parameters were evaluated, and it was found that the adsorption followed pseudo-second-order kinetic model with correlation coefficient 0.98. Freundlich and Langmuir model equations were used to analyse experimental data. The adsorption data fitted best with the Freundlich isotherm. In general, the quaternized polyacrylonitrile modified with clay (QPAN/MMT) is an auspicious adsorbent for MB dye removal.