Removal of some cationic dyes from aqueous solution by acrylamide- or 2-hydroxyethyl methacrylate-based copolymeric hydrogels


IŞIKVER Y.

FIBERS AND POLYMERS, cilt.18, ss.2070-2078, 2017 (SCI İndekslerine Giren Dergi) identifier identifier

  • Cilt numarası: 18 Konu: 11
  • Basım Tarihi: 2017
  • Doi Numarası: 10.1007/s12221-017-7215-7
  • Dergi Adı: FIBERS AND POLYMERS
  • Sayfa Sayıları: ss.2070-2078

Özet

In this study, anionic hydrogels were prepared using a crosslinker (N,N'-methylenebisacrylamide) through a free radical addition reaction in aqueous solutions of neutral acrylamide or 2-hydroxyethyl methacrylate monomer and anionic monomers, mesaconic acid or aconitic acid. Cationic dyes along with safranine (azine-), nile blue (oxazine-) and methylene blue (thiazine-) were selected as models of pollutants, and adsorption of these dyes onto the hydrogels was investigated. To examine the effect of concentration on adsorption, dye solutions prepared with a concentration range of 5-50 mg l (-1) and 0.1 g hydrogel at 25 A degrees C were exposed to the hydrogels until equilibrium was established. Dye adsorption onto the hydrogels was found to be an L type Giles adsorption isotherm. Monolayer sorption capacity and adsorption constant values were calculated from the Langmuir plots. To calculate R-L values, a non-dimensional analysis was used and they were always found to be 0 < R < 1. In other words, the hydrogels were favorable for adsorption of these dyes. Aqueous solutions of dyes were observed to interact with hydrogels in the following order: oxazine > azine > thiazine. Furthermore, the higher the number of carboxyl groups in the hydrogel composition, the higher the adsorbed amount of substance.