Abstract:The bioconcentration of 2,2',4,4',5-pentabromodiphenyl ether (BDE-99) by Chaetoceros muelleri in semi- continuous culture under different nitrogen concentrations was studied. The bioconcentration of BDE-99 by Chaetoceros muelleri was related to the nitrogen concentrations. With the increase of nitrogen concentrations, the bioconcentration content and bioconcentration factor declined. When the concentration of nitrogen was 0, 128, 512 μmol/L, the bioconcentration content per cell was 2.84, 2.38, 1.91 ng/106 cells, respectively; and the bioconcentration content per algal culture was 0.19, 0.16, 0.12 ng/mL, respectively. When nitrogen was 0 μmol/L, BCFlipid was 238.19×104 (ng/g)/(ng/mL). Pearson correlation analysis indicated the bioconcentration content per cell, algal culture and BCFlipid exhibited significantly negative correlation with nitrogen concentrations (r>-0.8, P0.8, P<0.05).