Effects of β-cyclodextrin on phytoremediation of soil co-contaminated with Cd and BDE-209 by arbuscular mycorrhizal amaranth

Pot experiments were conducted to investigate the effects of a series of beta-cyclodextrin (beta-CD) on phytoremediation of soil co-contaminated with Cd and BDE-209 by amaranth (Amaranthus hypochondriacus L) inoculated with arbuscular mycorrhizal fungus (AMF) - Rhizophagus intraradices. Results showed that the combination of mycorrhizal amaranth and 0.4% beta-CD (RI+beta(0.4)) significantly enhanced Cd concentrations and contents in shoots, total PBDEs concentration in roots, and BDE-209 dissipation in soil. Moreover, the RI+beta(0.4) treatment exerted the highest removal efficiency of both Cd and BDE-209. On the contrary, the xylem area, shoot Cd and BDE-209 concentrations and contents, and removal efficiency of Cd were markedly reduced in mycorrhizal amaranth with 0.8% or 1.2% beta-CD treatments (RI+beta(0.8), RI+beta(1.2)), compared with single inoculation treatment. The well-organized chloroplast and well-defined root anatomical structure were also observed in the treatment of RI+beta(0.4). Positive correlation was found between shoot biomass and chlorophyll concentrations. Shoot Cd or BDE-209 concentrations were positively correlated with xylem areas. In conclusion, mycorrhizal amaranth added with 0.4% beta-CD could be used for the decontamination of soil polluted with mixture of Cd and BDE-209 due to the higher chlorophyll concentration and the larger xylem area. (C) 2019 Elsevier Ltd. All rights reserved.