Abstract

The textile effluents have been considered as potential source of water contamination in the last few decades. Thus the effective methods were adopted for the removal of dyes and colorants from the textile effluents. In the present research, the removal of textile dye reactive red 223 (RR 223) was carried out by modified bentonite clay (MBC). The modification of bentonite clay was carried out by acid treatment method. The adsorption properties of MBC towards RR 223 were investigated using the batch method, at various temperatures 303-318 ±2 K under the optimized conditions. The adsorption equilibrium data were fitted in Langmuir, Freundlich and Dubinin-Radushkevich adsorption isotherm models and the values of the respective constants were evaluated by employing standard graphical method. From the correlation coefficient values (r²), it was founded that Langmuir model is the best fitted isotherm. Feasibility of adsorption process (R_L) and sorption energy (Es) was also determined. The pH_PZC of adsorbent was estimated by pH drift method. Thermodynamic parameters such as free energy (G^o), enthalpy (H^o) and entropy (S^o) of the system were calculated. Kinetics of dye removal was investigated that it follows pseudo second order rate constant. The surface morphology of adsorbent was observed by the Scanning Electron Microscope (SEM). The interaction forces involved between the adsorbent and adsorbate was determined by Fourier Transform Infrared Spectroscopy (FTIR). In addition the recovery of dye and regeneration of adsorbent was carried out by desorption experiments. The sorption and desorption capacity of MBC was found to be 95.15% and 78%.

This work is licensed under a Creative Commons Attribution 4.0 License.