The addition of nano zero-valent iron (nZVI) is a promising technology for the in situ remediation of soil.Unfortunately,the mobility and,consequently,the reactivity of nZVI particles in contaminated areas decrease due to their rapid aggregation.In this study,we determined how nZVI particles can be stabilized using different types of biochar (BC) as a support (BC@nZVI).In addition,we investigated the transport behavior of the synthesized BC@nZVI particles in a column filled with porous media and their effectiveness in the removal ofBDE209 (decabromodiphenyl ether) from soil.The characterization results of N2 Brmauer-Emmett-Teller (BET) surface area analyses,scanning electron microscopy (SEM),X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR) indicated that nZVI was successfully loaded into the BC.The sedimentation test results and the experimental breakthrough curves indicated that all of the BC@nZVI composites manifested better stability and mobility than did the bare-nZVI particles,and the transport capacity of the particles increased with increasing flow velocity and porous medium size.Furthermore,the maximum concentrations of the column effluent for bagasse-BC@nZVI (B-BC@nZVI) were 19％,37％and 48％ higher than those for rice straw-BC@nZVI (R-BC@nZVI),wood chips-BC@nZVI(W-BC@nZVI) and corn stalks-BC@nZVI (C-BC@nZVI),respectively.A similar order was found for the removal and debromination efficiency of decabromodiphenyl ether (BDE209) by the aforementioned particles.Overall,the attachment of nZVI particles to BC significantly increased the reactivity,stability and mobility of B-BC@nZVI yielded,and nZVI the best performance.