Biogenic synthesis of magnetic perlite@iron oxide composite: application as a green support for dye removal

Abstract

This study presents a method to synthesize magnetic expanded perlite composite through a co-precipitation method using single iron source and yellow pea as a reducing agent. The suggested method is environment friendly, easy, and biogenic. The combination of magnetite nanoparticles with expanded perlite and its modification with ibuprofen resulted in a new, cost-effective, and eco-friendly magnetic adsorbent for dye removal from contaminated streams. The prepared composite was characterized by point of zero charge (pH_zpc), X-ray diffraction, scanning electron microscopy, vibration sample magnetometer, and Fourier transforms infrared spectroscopy (FT-IR). The prepared adsorbent was used to remove Direct Red-81 as a target pollutant to test the feasibility of this idea, UV–vis spectroscopy was used to follow the adsorption process. The maximum adsorption was observed within 1 min at pH 4–6 using 30 mg of adsorbent. The experimental data were analyzed by the Langmuir and Freundlich adsorption models. Both models provided the best correlation of the experimental data and the maximum capacity was found to be 416.66 mg g⁻¹ under the optimized conditions. Desorption process of the anionic dye adsorbate was also investigated using ethanol as an eluent, and the volume of eluent was optimized.

Keywords:

• Dye removal
• Green chemistry
• Ibuprofen
• Magnetic composite
• Perlite

Acknowledgment

Support for this investigation by the Research Council of the University of Tehran through grants is gratefully acknowledged.