Macro-Reticular Ion Exchange Resins for Recovery of Direct Dyes from Spent Dyeing and Soaping Liquors

Mona M Naim; Nouf F Al-Harby; Mervette El Batouti; Mahmoud M Elewa

doi:10.3390/molecules27051593

Macro-Reticular Ion Exchange Resins for Recovery of Direct Dyes from Spent Dyeing and Soaping Liquors

Molecules. 2022 Feb 28;27(5):1593. doi: 10.3390/molecules27051593.

Authors

Mona M Naim¹, Nouf F Al-Harby², Mervette El Batouti³, Mahmoud M Elewa⁴

Affiliations

¹ Chemical Engineering Department, Faculty of Engineering, Alexandria University, Alexandria 21526, Egypt.
² Department of Chemistry, College of Science, Qassim University, Buraydah 51452, Saudi Arabia.
³ Chemistry Department, Faculty of Science, Alexandria University, Alexandria 21526, Egypt.
⁴ Arab Academy for Science, Technology and Maritime Transport, Alexandria P.O. Box 1029, Egypt.

Abstract

Dyes are a major class of organic pollutants that are well-known for their harmful impact on aquatic life and humans. Several new strategies for removing colours from industrial and residential effluents have recently emerged, with adsorption being the best option. The current study looked at the recovery of direct dyes from aqueous streams for reuse using macro-reticular ion exchange resins (IERs). The investigation includes dyeing single jersey cotton grey textiles with direct dyes from the Isma dye Company in Kafr El Dawar, Egypt. After centrifuging and separating the supernatant liquid, solutions from thirteen different dyes, produced at an average concentration between the wasted and soaping liquor concentrations, were calculated spectrophotometrically from the first dyeing trials. Kinetic data were well fitted with pseudo-second-order rate kinetics. The amounts of dye retained by the anion exchangers increased with a rise in temperature in the case of Strong Base Resin (SBR) and vice versa for Weak Base Resin (WBR). Batch adsorption experiments with SBR and WBR were conducted for each dye, and both Freundlich and Langmuir isotherms were constructed. It was found that adsorption obeyed both isotherms, that monolayer adsorption took place, and that the dye molecular weight, structure, and solubility, as well as the type of anionic resin used, had varying effects on the extent of absorption. The monolayer sorption capacities Q₀ determined from the Langmuir isotherm model for the strongly and weakly basic anion exchangers were found to be 537.6 and 692 mg/g for Direct Yellow RL, respectively. As a result, Yellow RL exhibited the greatest adsorption on both SBR and WBR. Orange GRLL, Blue 3B, and Congo Red, on the other hand, were the poorest colours absorbed by the IERs, whereas Blue RL demonstrated good adsorption by SBR and accelerated adsorption by WBR. Most of the dyes may be recovered and reused in this manner.

Keywords: adsorption isotherms; direct dyes; dye-house wastewater; macro-reticular ion exchange resins; recovery of dyes; wastewater treatment.