Phytoremediation of soil co-contaminated with Cd and BDE-209 using hyperaccumulator enhanced by AM fungi and surfactant.

Pot experiments were conducted to investigate the uptake and translocation of both Cd and decabromodiphenyl ether (BDE-209) in Solanum nigrum, under the treatments of two arbuscular mycorrhizal fungi [AMF, Funneliformis mosseae (FM) and Rhizophagus intraradices (RI)] and surfactant β-cyclodextrin (β-CD). Results showed that S. nigrum treated with either FM or β-CD significantly elevated shoot biomass and Cd concentrations and contents in shoots. The concentrations of BDE-209 in shoots and the dissipation and debromination efficiencies of BDE-209 in soil were significantly enhanced in S. nigrum treated with β-CD, inoculated with or without AMF. Moreover, significant positive correlations were found between the BDE-209 dissipation efficiency, the BDE-209 concentrations and contents in roots, and the soil enzymatic activities (polyphenol oxidase or dehydrogenase activities) and between the Cd and BDE-209 contents in shoots or roots. Higher concentrations of lower-brominated products and total PBDEs were detected in shoots than in roots suggesting that BDE-209 might be initially absorbed by roots, then translocated to shoots, and then degraded into lower brominated products in shoots. Considering the plant uptake of Cd and BDE-209 and the efficient removal of those chemicals in soils, the combination of S. nigrum and β-CD inoculated with or without AMF may be viable alternatives for phytoremediation of the co-contaminated soil.