Remediation of phenanthrene contaminated soil by g-C3N4/Fe3O4 composites and its phytotoxicity evaluation

Abstract

This work is a premier demonstrating the technical feasibility of remediation of PAHs-contaminated soil by g-C₃N₄/Fe₃O₄. g-C₃N₄/Fe₃O₄ has been synthesized by typical two steps involved the synthesis of g-C₃N₄ and the subsequent in situ co-precipitation of Fe₃O₄ nanoparticles. g-C₃N₄/Fe₃O₄ exhibits excellent visible-light-driven photocatalytic activity for the degradation of phenanthrene in soil at circumneutral pH. The enhanced photocatalytic activity of g-C₃N₄/Fe₃O₄ should be attributed to the hybrid of Fe₃O₄ and g-C₃N₄ and appropriate Fe₃O₄ loading amount can improve not only the visible light absorption ability but also the separation of the photo-induced electron-hole pairs. The phytotoxicity evaluation, a preliminary ecological risk assess, was conducted on lettuce cultivation experiments. Base on the data of growth indexes including seeds germination percentage, root length, leaf length, and fresh weight of lettuce, it can be conclude that photocatalytic oxidation based on g-C₃N₄/Fe₃O₄ provide a mild oxidation process to degrade the phenanthrene from contaminated soil and there is no negative impact on the growth of lettuce. This work definitely demonstrates that this soil remediation method based on g-C₃N₄/Fe₃O₄ is technologically feasible and has immense potential in the application of remediation of organic pollutant contaminated soils.

Keywords: Photocatalysis; Phytotoxicity; Polycyclic aromatic hydrocarbons; Remediation of soil; g-C(3)N(4).