Superior removal of methylene blue using green fabricated pomegranate peel/nano-hematite composite: reusability, isotherm and kinetics study

Abstract

Green hematite nanoparticles were synthesized using pomegranate peel extract of different concentrations (2 g, 4 g, and 6 g) and in the presence of the peel residuals. The obtained products defined as PP/GNH (I), PP/GNH (II), and PP/GNH (III) referring to the hematite nanoparticles at different concentrations compositing with pomegranate peel residuals. The products were addressed as green adsorbents for methylene blue dye contaminants in water. They exhibit superior adsorption properties with theoretical q_max of 666, 1111, and 909 mg/g for PP/GNH (I), PP/GNH (II), and PP/GNH (III), respectively. The equilibration times were attained after 480 min for the three products. The isotherm and kinetic studies indicate that the adsorption systems for the synthetic materials are of chemisorption type. The adsorption behaviors of these systems can be demonstrated according to Pseudo-second order as well as Elovich kinetic model. Furthermore, the adsorption results reflected a mono-layer uptake form which was more suitable for the Langmuir model than other investigated models. The products also showed high performances when it comes to remove the dyes investigated such as methylene blue Congo red, safranin, methyl orange, and crystal violet. Finally, green fabricated nano hematite/pomegranate peel composites are of high stability and can be reused for five cycles.

Communicated by Ramaswamy H. Sarma

Keywords:

• Green hematite
• pomegranate peel
• dyes
• reusability
• kinetic modeling

Acknowledgements

This project was funded by the Deanship of Scientific Research (DSR), King Abdulaziz University, Jeddah, Saudi Arabia under grant no. (KEP-7-130-40). The authors, therefore, acknowledge with thanks DSR for technical and financial support.

Author’s contribution

All the authors are actively involved in Conceptualization; Data curation and analysis; Investigation; Methodology; Visualization; Writing manuscript; reviewing editing. validation of results, and proofreading.

Disclosure statement

On behalf of all authors, the corresponding author states that there is no conflict of interest.