Removal of Cationic Crystal Violet dye using Zeolite‐ Embedded Carboxymethyl Tamarind Kernel Gum (CMTKG) based Hydrogel Adsorbents

Abstract

In this research paper, various formulations of zeolite‐loaded carboxymethyl tamarind kernel gum (CMTKG) based hydrogels were synthesized and utilized as a potential adsorbent for the removal of crystal violet (CV) dye. The swelling capacity of all the synthesized hydrogels was investigated and the composition of hydrogel which exhibited maximum swelling was used for the characterization and dye removal experiment. The CV dye was chosen as a model dye for the dye removal experiment. The structure of zeolite and zeolite embedded hydrogel was elucidated by XRD, FTIR, FE‐SEM, EDX and elemental papping techniques. The adsorption experiment was investigated by varying the CV concentration, amount of hydrogel adsorbent, temperature, pH of the dye solution, adsorption time, and ionic strength. The Langmuir and Freundlich isotherm models were used to fit the adsorption data and it was observed that the data fitted well with the Langmuir model. Moreover, hydrogel‘s maximum dye adsorption efficiency was found at 123.60 mg g−1. The adsorption kinetic studies were followed by pseudo‐ first‐order and intraparticle diffusion kinetic models. In addition, regeneration studies were performed for the best adsorbent hydrogel using ethanol solvent and the result concluded the desorption efficiency of hydrogel (82 %) over four desorption cycles.

Magnetic, Biocompatible and Biodegradable Carboxymethyl Cellulose‐Based Hydrogel for Cationic Dye Adsorption

“…The adsorption data was fitted to these models, and the model with the highest correlation coefficient (R 2 ) was selected. The Langmuir isotherm model represents the saturated adsorption process and monolayer adsorption, while the Freundlich model generally demonstrates multilayer adsorption and shows that adsorption heat distributions non‐uniformly [53–55] . The mathematical equations of the Langmuir and Freundlich isotherm models in their non‐linear form are as follows: $$$\vcenter{\openup.5em\halign{$\displaystyle{#}$\cr {q}_{e}={{{q}_{m}b{C}_{e}}\over{1+b{C}_{e}}}\hfill\cr}}$$$ $$$\vcenter{\openup.5em\halign{$\displaystyle{#}$\cr {q}_{e}={K}_{F}{C}_{e}^{1/n}\hfill\cr}}$$$ …”

“…The Langmuir isotherm model represents the saturated adsorption process and monolayer adsorption, while the Freundlich model generally demonstrates multilayer adsorption and shows that adsorption heat distributions non-uniformly. [53][54][55] The mathematical equations of the Langmuir and Freundlich isotherm models in their non-linear form are as follows:…”