Abstract: Phytoremediation of soil contaminated with phenanthrene and pyrene
was investigated using twelve plant species. Plant uptake and accumulation of
these chemicals were evaluated. At the end of the experiment (45 d), the
remaining respective concentrations of soil phenanthrene and pyrene in spiked
vegetated soils, with initial phenanthrene of 133.3 mg/kg and pyrene of 171.5
mg/kg, were 8.71–16.4 and 44.9–65.0 mg/kg, generally
4.7%–49.4% and 7.1%–35.9% lower than their concentrations in the
nonvegetated soils. The loss of phenanthrene and pyrene in vegetated spiked
soils were 88.2%–93.0% and 62.3%–73.8% of the added amounts of these
contaminants, respectively. Although plant uptake and accumulation of these
compounds were evident, and root concentrations and RCFs (root concentration
factors; defined as the ratio of PAH concentrations in roots and in the soils
on a dry weight basis) of these compounds significantly positively correlated
to root lipid contents, plant uptake and accumulation only accounted for less
than 0.01% and 0.23% of the enhanced loss of these chemicals in vegetated
versus non-vegetated soils. In contrast, plant-promoted microbial
biodegradation was the dominant mechanism of the phytoremediation for soil
phenanthrene and pyrene contamination. Results from this study suggested a
feasibility of the establishment of phytoremediation for soil PAH
contamination.