ISSN: 2577-4360
Authors: Abu Shammala F*
New sodium alginate/gelatin/graphene oxide (SGGO) nanocomposite materials were prepared using a “hydrophilic assembly– sustained release gelation†two-step method. The obtained materials were utilized as nano-adsorbents for the elimination of cationic dyes methylene blue (MB) and crystal violet (CV) and anionic dye Eriochrome black T (EBT). The influence of pH, amount of adsorbent, initial dye concentration and contact time was studied. Results indicated that the optimum pH for removal of the dyes was between 7.0-8.0, and showed excellent regeneration capacity. The SGGO nanocomposite aerogel has densities as low as 16.5 mg/cm3, superior porosity (92.5%), and abundant functional groups when only 5 wt% GO was incorporated. The results showed that when the dosage of the adsorbent was 1.0 g, pH of the solution was 7, temperature was 3°C, initial concentration of dyes was 250 mg L−1, and adsorption time was 180 min, yielding the maximum monolayer adsorption capacity of 255.12 mg/g, 175.34 mg/g, and 115.42 mg/g for Crystal violet (CV) Methylene blue (MB), and Eriochrome black T (EBT), respectively. The adsorption isotherms obeyed the Langmuir isotherm models for the adsorption, thermodynamic parameters showed that the adsorption process was spontaneous and endothermic in nature. Moreover, the adsorption kinetics of MB and CR onto SGGO followed a pseudo-second-order kinetic model, indicating that the chemical adsorption was the rate-limiting step. Thermodynamic parameters, such as Gibbs energy (ΔG°), enthalpy (ΔH°), and entropy (ΔS°).
Keywords: Adsorbent; Sodium alginate; Gelatin; Graphene oxide; Dyes; Microextraction
