Adsorption kinetics of methylene blue dyes onto magnetic graphene oxide

• Published in: Journal of environmental chemical engineering 2018-04, Vol.6 (2), p.2803-2811
• Main Authors: Othman, Nur Hidayati, Alias, Nur Hashimah, Shahruddin, Munawar Zaman, Abu Bakar, Noor Fitrah, Nik Him, Nik Raikhan, Lau, Woei Jye
• Format: Article
• Language: English
• Subjects: Adsorption; Fe3O4; Graphene oxide; Magnetic separation; Methylene blue dye
• ISSN: 2213-3437; 2213-3437
• DOI: 10.1016/j.jece.2018.04.024

•The preparation and characterization of graphene oxide- magnetic iron oxide nanoparticles (GO-MNP) have been outlined.•The use of GO-MNP as high efficient adsorbent for removal of methylene blue dye from polluted water.•Adsorption kinetics and equilibrium isotherm models for MB dye were reviewed. Adsorption is one of the most effective methods for the treatment of wastewater containing dyes owing to its low operating cost, simplicity of process design and smaller amounts of harmful substances. In this work, graphene oxide- magnetic iron oxide nanoparticles (GO-MNP) was synthesized using sonomechanical technique and used as effective adsorbent for synthetic methylene blue (MB) dye removal. Batch adsorption experiments were performed with the variation of initial MB dye concentration, pH solution, adsorbent dosage and contact time. The adsorbent showed significant removal efficiency around 99.6% for MB. It was found that the removal rate of MB dye in the solution was higher when higher pH, larger dosage of adsorbent in solution and longer contact time were used. A regenerative study was carried out and minor reduction in adsorption capacity of the regenerated GO-MNP was observed after 2 cycles. Analysis of adsorption equilibrium revealed that the data is well fitted with Langmuir and Freundlich adsorption isotherm model (R2 > 0.97), indicating multi layer adsorption of dye on the surface of adsorbent. In the case of adsorption kinetics, the GO-MNP adsorbent follows pseudo-second order kinetics model showing R2 > 0.999, whereas for pseudo-first order kinetics model, the value of R2 was significantly lower. The finding of the present work highlights simple fabrication of magnetic GO and its application as efficient and magnetically separable adsorbent for environmental clean-up.