Photocatalytic degradation of phenanthrene and pyrene on soil surfaces in the presence of nanometer rutile TiO 2 under UV-irradiation

Abstract

Photocatalytic degradation of phenanthrene and pyrene on soil surfaces in the presence of nanometer rutile TiO 2 was investigated. After being spiked with phenanthrene and pyrene, soil samples loaded with different dosages of nanometer rutile TiO 2 (0, 1, 2, 3, and 4 wt%) were exposed to UV-irradiation for 25 h. The results indicated that the photocatalytic degradation of phenanthrene and pyrene followed the pseudo-first-order kinetics. The catalyst dosage of 2 wt% was chosen as the optimal one for further studies. According to the half-life, the degradation rate of the phenanthrene and pyrene on soil surfaces was related to their absorption spectra in soil and oxidation-half-wave-potential. In addition, the degradation of phenanthrene and pyrene increased along with increasing H 2O 2, light intensity and humic acids. All results indicated that the photocatalytic method in the presence of nanometer rutile TiO 2 was an advisable choice for the treatments of PAHs polluted soil in the future.