Ultrasonic-assisted synthesis of superabsorbent hydrogels based on sodium lignosulfonate and their adsorption properties for Ni2+

Abstract

Nowadays, the attention of both academic and industrial research is paid to the novel materials based on renewable organic resources. Sodium lignosulphonate (SLS) is selected in this study to synthesize novel superabsorbent hydrogels by ultrasonic polymerization. The structure, morphology and stability of SLS-based hydrogel were confirmed by Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM) and thermogravimetric analysis (TGA). Under the optimal condition, SLS-based hydrogel possesses the water absorbency of 1328g·g in distilled water and 110g·g in 0.9wt% NaCl solution. In addition, the prepared SLS-hydrogel as an adsorbent was applied to remove Ni from an aqueous solution in virtue of its low cost and favorable adsorption capacity. The various experimental conditions that influence the adsorption capacity were investigated such as temperature (20-60°C), pH (2.0-7.0), contact time (0-360min) and initial concentration of the Ni solution (100-600mg·L). Then the adsorption capability could reach 293mg·g under optimal conditions. The results revealed that the adsorption behavior is spontaneous and endothermic. Furthermore, it was observed that the adsorption mechanism and adsorption equilibrium data obeyed pseudo-second-order kinetic and Freundlich models.

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Preparation and anti‐evaporation properties of organic–inorganic superabsorbent based on Tragacanth gum and clay

“…The pseudo‐second‐order swelling kinetics was based on swelling equilibrium. The model 42 was expressed by formula (): where SR e and SR represent the swelling ratio at the swelling equilibrium and swelling ratio at time t, respectively and K 1 and K 2 are the rate constants, R 2 was the linear correlation coefficient. Figures 6(b),(c) presents the fitting of the experimental data with pseudo‐first‐order and pseudo‐second‐order equations, respectively.…”

Novel Fe3O4–poly(methacryloxyethyltrimethyl ammonium chloride) adsorbent for the ultrafast and efficient removal of anionic dyes

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