Facile preparation of magnetic separable powdered-activated-carbon/Ni adsorbent and its application in removal of perfluorooctane sulfonate (PFOS) from aqueous solution

Abstract

The main aim of this study was to synthesize magnetic separable Nickel/powdered activated carbon (Ni/PAC) and its application as an adsorbent for removal of PFOS from aqueous solution. In this work, the synthesized adsorbent using simple method was characterized by using X-ray diffractionometer (XRD), surface area and pore size analyzer, vibrating sample magnetometer (VSM), and high resolution transmission electron microscope (HRTEM). The surface area, pore volume and pore size of synthesized PAC was 1521.8 m²g⁻¹, 0.96 cm³g⁻¹, 2.54 nm, respectively. Different kinetic models: the pseudo–first-order model, the pseudo–second-order model, and three adsorption isotherms—Langmuir, Freundlich and Temkin—were applied to study the sorption kinetics and isothermal behavior of PFOS onto the surface of an as-prepared adsorbent. The rate constant using the pseudo–second-order model for removal of 150 ppm PFOS was estimated as 8.82×10⁻⁵ and 1.64×10⁻⁴ for PAC and 40% Ni/PAC, respectively. Our results demonstrated that the composite adsorbents exhibited a clear magnetic hysteretic behavior, indicating the potential practical application in magnetic separation of adsorbents from aqueous solution phase as well.

Keywords:

• PFOS
• Ni/PAC compound
• adsorption
• magnetism

Acknowledgments

This work was finically supported by the National Natural Science Foundation of China (No: 51172109) and the Natural Science Foundation of Jiangsu Province of China (No: BK2010497).