Simple and green fabrication of recyclable magnetic highly hydrophobic sorbents derived from waste orange peels for removal of oil and organic solvents from water surface

Abstract

This study presents the preparation and characterization of natural waste material (orange peel) derived low cost, bio-based, recyclable, highly hydrophobic/superoleophilic magnetic sorbents to treat environmental pollution caused by oils and organic contaminants from water. Orange peels were dried, powdered and converted into magnetic and highly hydrophobic/superoleophilic sorbents by the incorporation of Fe3O4 nanoparticles using co-precipitation approach and subsequently modifying with low surface energy polydimethylsiloxane (non-fluorinated hydrophobic reagent) layers. SEM, EDS, XRD, FTIR, XPS, TGA, VSM and contact angle measurements analysis were used for characterization of the developed materials. The as-prepared sorbents exhibit strong magnetic behavior with saturation magnetization (Ms) value of 14.9 emu/g, excellent hydrophobicity with water contact angle of 149.2° and very high capacity for the selective absorption of various oils and organic solvents from oil contaminated water. It has high absorption capacity up to 5.11 and 6.90 times its original weight for diesel oil and engine oil respectively, along with high recyclability of more than eight cycles and the advantage of magnetic separation from water surface after absorption of oils. Thus, the orange peel waste derived absorbent with magnetic and high hydrophobic properties is a promising alternative for the capture of oil and organic pollutants from water.