The extensive industrial use of brominated flame retardants has aroused rapidly growing public concerns about their ubiquity in the environment. The feasibility of uptake and translocation of decabromodiphenyl ether (BDE-209) by three rice cultivars, namely Fengmeizhan, Hefengzhan and Guangyinzhan, and the uptake mechanisms of BDE-209 into rice roots, were investigated by employing a partition-limited model. Uptake of BDE-209 by the rice cultivars (Fengmeizhan, Hefengzhan and Guangyinzhan) was examined by a 60-day cultivation in sterilized BDE-209 spiked sand, followed by Soxhlet extraction and gas chromatography-mass spectrometry (GC-MS) analysis. A partition-limited model was applied for estimating and describing the approach of the uptake of BDE-209 by rice in sand. The average quasi-equilibrium factor (αpt) of BDE-209 in root uptake in sand was 0.112×10(-3) for three rice cultivars in the present study (<1), implying a non-equilibrium movement of molecules and a dominated passive transport uptake. According to the results of sorption analysis of dead and fresh roots, apoplastic pathway likely dominated the transport of BDE-209 into roots cells.
Keywords: Apoplastic path; Brominated flame retardants; Partition-limited model; Quasi-equilibrium factor.
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