Adsorbent materials based on a geopolymer paste for dye removal from aqueous solutions

Abstract

Geopolymers are porous materials that can be used as basic dye adsorbents in wastewater treatment. In this work, a green geopolymer paste synthesized from industrial and agricultural waste materials was employed as an adsorbent to remove the basic dye methylene blue from aqueous solutions. The geopolymer sample was characterized by X-ray fluorescence, scanning electron microscopy, Brunauer Emmet Teller surface area measurements, and particle size techniques. The isotherms of dye adsorption by the geopolymer sample were considered by the Langmuir and Freundlich adsorption models. The removal efficiency increased with increasing geopolymer dosage, contact time and temperature. The Freundlich isotherm exhibited the best fit to the adsorption data.