Search results for "geopolymeerit"
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Alkali-Activated Adsorbents from Slags: Column Adsorption and Regeneration Study for Nickel(II) Removal
2021
Alkali-activated adsorbents were synthesized by mixing three different slags from the steel industry: blast furnace slag (BFS), ladle slag (LS), and Lintz–Donawitz converter slag (LD). These powdered slag-based geopolymers (GP) were used to remove nickel(II) from aqueous solutions in fixed-bed column studies. The experiments were conducted in pH 6 using a phosphate buffer with initial nickel(II) concentration of 50 mg/L. Samples were taken at time intervals of between 5 and 90 min. Three adsorption–desorption cycles were implemented with a flow rate of 5 mL/min. The geopolymers were characterized by Fourier-Transform Infrared Spectroscopy (FTIR), X-ray powder diffraction (XRD), Field Emissi…
Column Adsorption Studies for the Removal of Ammonium Using Na-Zeolite-Based Geopolymers
2022
The aim of this study was to examine the removal of ammonium ions from a synthetic model solution by using Na-zeolite-based geopolymers. Na-zeolite (=analcime) is a residue from mining industry. Three adsorbents were prepared from Na-zeolite using different production steps and metakaolin as a blending agent. These novel adsorbents were investigated in a fixed-bed column system where the effects of different flow rates with the initial ammonium concentration of 40 mg/L were studied. The Thomas, Bohart–Adams and Yoon–Nelson breakthrough curve models fitted well with the experimental data with a high R2 value. After adsorption experiments, adsorbents were regenerated using a mixture of 0.2 M …