Affiliations: Department of Resource and Environment, Huangshan
University, Huangshan 245000, China | Department of Environmental Engineering, Zhejiang
University, Hangzhou 310029, China
Abstract: Phytoremediation has long been recognized as a cost-effective method
for the removal of polycyclic aromatic hydrocarbons (PAHs) from soil. A study
was conducted to investigate the uptake and accumulation of PAHs in root and
shoot of Lolium perenne L. Pot experiments were conducted with series of
concentrations of 3.31–378.37 mg/kg for phenanthrene and those of
4.22–365.38 mg/kg for pyrene in a greenhouse. The results showed that
both ryegrass roots and shoots did take up PAHs from spiked soils, and
generally increased with increasing concentrations of PAH in soil.
Bioconcentration factors (BCFs) of phenanthrene by shoots and roots were
0.24–4.25 and 0.17–2.12 for the same treatment. BCFs of pyrene by
shoots were 0.20–1.5, except for 4.06 in 4.32 mg/kg treatment, much lower
than BCFs of pyrene by roots (0.58–2.28). BCFs of phenanthrene and pyrene
tended to decrease with increasing concentrations of phenanthrene and pyrene in
soil. Direct uptake and accumulation of these compounds by Lolium perenne L.
was very low compared with the other loss pathways, which meant that
plant-promoted microbial biodegradation might be the main contribution to
plant-enhanced removal of phenanthrene and pyrene in soil. However, the
presence of Lolium perenne L. significantly enhanced the removal of
phenanthrene and pyrene in spiked soil. At the end of 60 d experiment, the
extractable concentrations of phenanthrene and pyrene were lower in planted
soil than in non-planted soil, about 83.24%–91.98% of phenanthrene and
68.53%–84.10% of pyrene were removed from soils, respectively. The
results indicated that the removal of PAHs in contaminated soils was a feasible
approach by using Lolium perenne L.
Keywords: phytoremediation, polycyclic aromatic hydrocarbons (PAHs), phenanthrene and pyrene, uptake and accumulation
