Adsorption behavior of phenanthrene in soil amended with modified loofah sponge

Abstract

The aim of the research was to assess the feasibility of adding modified loofah sponge to increase bioavailability and enhance the removal of phenanthrene (Phe) in soil environment. High temperature and pressure (0.125 MPa, 130 °C) could significantly increase the wrinkles, surface area of loofah sponge (142.35 m2 g−1), and this modification improved Phe adsorption on the loofah sponge. Carbon content in the modified loofah sponge increased to 46.53%. After the modified loofah sponge was added to the Phe-contaminated soils, the overall adsorption of Phe onto the mixture increased. However, due to the existence of competitive adsorption, the adsorption of Phe by soil decreased. The addition of modified loofah sponges in the soils significantly influenced the behavior and adsorption potential of Phe for different initial concentration in the soil. Compared with at pH 7, the migration of Phe from soil to modified loofah sponge increased at pH 6 or 8. The pseudo-second-order kinetic showed an excellent fitness with the experimental kinetic data in describing Phe dynamic adsorption on the modified loofah sponge. The possible mechanism of Phe retention on modified loofah sponge was chemical adsorption. These results from this study will improve knowledge on understanding the adsorption mechanism of Polycyclic aromatic hydrocarbons (PAHs) onto biomass materials in soil and provide a theoretical foundation for using modified loofah sponge as a green cost-effective sorbent to remediate PAHs-contaminated soil.