Physicochemical interactions in C.I. Acid Green 16 – Lewatit S 6368 A systems – kinetic, equilibrium, auxiliaries addition and thermodynamic aspects

Abstract

Batch and column methods as well as spectroscopic, surface tension and conductivity measurements were used to establish interactions between the C.I. Acid Green 16 dye (AG16) and the strongly basic anion exchange resin Lewatit S 6368 A (6368A) of polystyrene matrix in the presence of selected auxiliaries. Equilibrium and kinetic studies were carried out in a wide range of experimental conditions such as dye and auxiliaries concentrations, temperature or phase contact time. Next, the adsorption parameters were calculated using the Freundlich, Langmuir, Temkin and Dubinin-Radushkevich isotherm models as well as the pseudo-first order, pseudo-second order and intraparticle diffusion models. It was found that the sorption capacities of the resin increase from 625.2 to 811.6 mg/g with the temperature increase from 293 to 333 K. AG16 uptake decrease with the anionic (SDS) and nonionic (TX100) surfactant addition. There is also a strong sorption of only SDS on 6368A as well as AG16-SDS complexes/aggregates which are less conducting after sorption than before. After sorption at higher temperatures there are also more (non-associated) AG16 ions in the TX100 solution than in the SDS one which has an important effect on sorption and desorption processes. Resin regeneration can be procced using 1 M HCl or 1 M NaCl in 50%v/v MeOH with the 99.07–92.6% and 88.75–80.0% yield, respectively.