Preparation of composite hydrogels containing fly ash as low-cost adsorbent material and its use in dye adsorption


Onder A., Ilgin P., Ozay H., Ozay O.

INTERNATIONAL JOURNAL OF ENVIRONMENTAL SCIENCE AND TECHNOLOGY, 2021 (Journal Indexed in SCI) identifier identifier

  • Publication Type: Article / Article
  • Publication Date: 2021
  • Doi Number: 10.1007/s13762-021-03622-6
  • Title of Journal : INTERNATIONAL JOURNAL OF ENVIRONMENTAL SCIENCE AND TECHNOLOGY
  • Keywords: Composite hydrogel, Fly ash, Methylene blue, Methyl orange, Isotherm, Kinetics, METHYLENE-BLUE, REMOVAL, WATER, PH, NANOCOMPOSITES, MICROSPHERES, CELLULOSE

Abstract

Recycling industrial wastes is necessary for the economy and the environment. Additionally, it is important to develop high-efficiency adsorbents to prevent severe water pollution caused by wastewater containing dye agents. Here, poly(2-acrylamido-2-methylpropane sulfonic acid)-fly ash composite hydrogel was synthesized with a variety of fly ash proportions with the radical polymerization method. The synthesized composite hydrogel was used for adsorption of methylene blue and methyl orange dyes from water containing dye agents. A variety of parameters such as initial dye concentration, solution pH, anion effects, temperature, contact time and adsorbent amount were investigated for optimization of the adsorption process. The poly(2-acrylamido-2-methylpropane sulfonic acid)-fly ash composite hydrogel was determined to be an effective adsorbent to remove both the cationic dye methylene blue (1438.68 mg g(-1)) and the anionic dye methyl orange (646.54 mg g(-1)). Experimental adsorption data were assessed with a variety of isotherm and kinetic models. It was determined that the adsorption of both dye molecules abided by the pseudo-second-order kinetic model. The thermodynamic parameters were determined as Delta H degrees = - 15.77 +/- 5.22 kJ mol(-1), Delta S = - 45.05 +/- 16.42 J mol(-1) K-1 and Delta G degrees < 0 for MB, Delta H degrees = - 20.13 +/- 4.83 kJ mol(-1), Delta S = - 72.87 +/- 15.20 J mol(-1) K-1 and Delta G degrees > 0 for MO. In conclusion, a material was synthesized that can be used as a single adsorbent composite material for both anionic and cationic dyes. In addition to the perfect adsorption capacity of this material, it offers reusability and a broad area of application for a variety of dye agents.