Fabrication and characterization of starch-cl-poly(Lactic acid-g-acrylamide) nanohydrogel for adsorptive removal of eriochrome black-t from the aqueous medium

Abstract

In this paper, starch-cl-poly(lactic acid-g-acrylamide) nanohydrogel(ST-cl-poly(LA-g-AAm) (NHG) was fabricated using co-graft/crosslinking polymerization method. Synthesized nanohydrogel has been characterized by Fourier-transform infrared spectroscopy (FTIR), transmission electron microscopy (TEM), and scanning electron microscopy (SEM). It has been found to be a proficient adsorbent for the elimination of highly noxious Eriochrome Black T (EBT) from aqueous solution. Effect of various parameters such as concentration of adsorbate, temperature, pH, contact time and adsorbent dosage was thoroughly studied. The highly acidic medium was found to be an operative medium for the maximum adsorption. Isotherm studies revealed that Langmuir model explained better adsorption process compared to those of Freundlich and Temkin indicating the monolayer adsorption of EBT onto ST-cl-poly(LA-g-AAm) NHG. Kinetic studies have shown that the adsorption can be better explained by pseudo-first-order kinetics.