Uptake and accumulation of phenanthrene and pyrene in spiked soils by Ryegrass (Lolium perenne L.).
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.
Xu
Sheng-you
SY
Department of Environmental Engineering, Zhejiang University, Hangzhou 310029, China. shengyouxu22@yahoo.com.cn
Chen
Ying-xu
YX
Lin
Qi
Q
Wu
Wei-xiang
WX
Xue
Sheng-guo
SG
Shen
Chao-fengi
CF
D000704:Analysis of Variance; D001673:Biodegradation, Environmental; D004787:Environmental Pollution / Q000517:prevention & control*; D008129:Lolium / Q000378:metabolism*; D010616:Phenanthrenes / Q000493:pharmacokinetics*; D011721:Pyrenes / Q000493:pharmacokinetics*; D012987:Soil / Q000032:analysis*; D012988:Soil Microbiology; D012989:Soil Pollutants / Q000493:pharmacokinetics*
D010616:Phenanthrenes; D011721:Pyrenes; D012987:Soil; D012989:Soil Pollutants; C031181:phenanthrene; C030984:pyrene