| In our previous study, a column experiment with horizontal permeable barriers was conducted to investigate DTPA-assisted phytoextraction of heavy metals by turfgrass from air dried sludge and associated heavy metal leaching. Thus, large amounts of leachates contained excessive heavy metals were obtained. In order to avoid the leachate pollute the environment and to utilize it, Lolium perenne was cultivated by the leachates and the effects of the leachates on initial growth and heavy metal accumulation were investigated. The results showed that the leachates were rich in inorganic mineral nutrients for plant growth. Compared to the control, the leachate obtained from the treatment of 20 mmol·kg-1 DTPA in the absence of turfgrass planting significantly inhibited seed germination, delayed germination peak and decreased aboveground biomass. But there was no significant differences between other treatments and control. All leachate treatments significantly increased chlorophyll content, which is increased by 91.2% in the leachate from the treatment of 10 mmol·kg-1 DTPA in the presence of barrier. For heavy metal accumulation, the leachates significantly increased Cd, Cr, Cu, Zn and Pb concentrations in turfgrass shoots and roots, especially the treatment of 20 mmol·kg-1 DTPA in the absence of turfgrass planting. With respect to the same metal, metal concentration in root was higher than that in shoot under the same treatment. The bioconcentration factor（BCF） of heavy metals for shoots showed the biggest for Zn and smallest for Pb. However, BCF for roots showed higher for Cd, Pb and lower for Zn. Also, zinc showed strong transfer ability from root to shoot among the five metals. It was considered that relative to the other four heavy metals, Lolium perenne could be selected as a potential candidate for the phytoextraction of soil contaminated with Zn. |
