Phytoremediation of Polychlorinated Biphenyls Contaminated Soil by Leguminosae-Gramineae Intercropping: A Field Trial
多氯联苯污染土壤的豆科-禾本科植物田间修复效应

Phytoremediation of polychlorinated biphenyls (PCBs) contaminated soil by leguminosae (alfalfa) and gramineae (ryegrass and tall fescue) was studied in a field trial. All planted treatments had significantly higher PCBs removal efficiency compared with those of unplanted control after 270 days of in-situ phytoremediation. Alfalfa monoculture received the highest removal efficiency of soil PCBs by 59.6%. Analysis of PCBs congeners composition showed that the percentage of di-chlorinated biphenyl decreased in all planted treatments. Alfalfa produced the maximum biomass among the 3 plants. Total PCBs concentration in alfalfa roots reached 355.1 microg/kg, which was significantly higher than those in ryegrass and tall fescue. The phytoextraction efficiency of different treatment was in order of alfalfa > alfalfa-ryegrass-tall fescue > alfalfa-ryegrass > ryegrass > alfalfa-tall fescue > tall fescue. The results suggest that alfalfa may be an ideal candidate for the phytoremediation of PCBs contaminated soil.