Document Type : Research Paper
Authors
1 Department of Chemistry, Ignatius Ajuru University of Education, Rivers State, Nigeria
2 Department of Industrial Chemistry, Enugu State University of Science and Technology,Enugu State, Nigeria.
Abstract
The study describes the removal of iron(II) ions from aqueous solutions using characterized cellulose derived from Pentaclethra macrophylla Benth pod, as well as the adsorption isotherm, thermodynamic, and kinetic analyses of Fe(II) ion on raw and isolated cellulose. Cellulose was isolated from the pod of Pentaclethra macrophylla Benth via delignification and bleaching. X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier Transform Infrared Spectrometry (FTIR), Brunauer–Emmett–Teller (BET) analysis were used to characterize the raw and isolated cellulose. The adsorbents were further characterized using adsorption isotherms, kinetics, and thermodynamic models. The isolated cellulose has better thermal stability, crystallinity, and porosity than the raw. The crystallinity index of isolated cellulose was estimated at 32.4%. From the findings, Fe(II) removal was around 95.33% at 30°C, 93% at 150 minutes contact time, 87.34% at the initial concentration of metal ions of 50 mg/g, and 78.20% at a pH of 8. The isotherms data were consistent with all models, but the Feundlich and Temkin models fit better than the Langmuir isotherm. This is the basis that the R2 in both the Feundlich and Temkin models were at the range of 0.9109–0.9992. The ΔG° values for Fe(II) in cellulose increased with increasing temperature and were all less than -5 kJ/mol. Thus, it implies physical adsorption and exothermic processes. The adsorption of Fe(II) with cellulose followed a pseudo-second-order adsorption. The results suggest that Pentaclethra macrophylla Benth pod has a high possibility of being used as an effective and economical adsorbent for the removal Fe(II) ion
Keywords
Main Subjects
)