Stearic acid-modified magnetic porous hydroxyapatite microspheres for efficient marine oil spill treatment

The escalating threats posed by industrial wastewater discharge and offshore crude oil spills necessitate the development of cost-effective, environmentally friendly adsorbents. In this study, stearic acid-modified (SA) magnetic porous hydroxyapatite (HAP) microspheres were prepared by hydrothermal synthesis. Abalone shell particles were employed as the calcium source, and Fe 3 O 4 nanoparticles (nFe 3 O 4 ) or industrial iron tetraoxide particles (Fe 3 O 4 ) were selected as the magnetic source. The microsphere (SA/nFe 3 O 4 -HAP) demonstrated enhanced superhydrophobicity, lipophilicity and increased specific surface area, with an oil absorption capacity of 6.518 g/g. Notably, compared to SA/Fe 3 O 4 -HAP, the magnetic particles on SA/nFe 3 O 4 -HAP exhibited more even dispersion. The excellent superparamagnetism and hydrophobicity of SA/nFe 3 O 4 -HAP facilitated its dispersion in crude oil, enabling efficient magnetic separation. After five cycles, the adsorption efficiency remained high 4.213 g/g, signifying its good recyclability. In conclusion, this environmentally friendly adsorbent demonstrates synergistic efficacy in addressing marine oil spills and discarded shell pollution, offering a potential balance between environmental and economic benefits.