摘要：An isolated bacteria named as EW1 with Cr(VI) tolerance up to 500 mg/L was identified as Bacillus sp. based on biochemical features and 16S rRNA gene sequencing. Under the optimum condition with pH of 7, inoculation amount of 4% and T of 35 V , 99.4% Cr(VI) removal efficiency was achieved with initial Cr(VI) concentration of 50 mg/L. In addition, it was found that Cr(VI) removal rate constant decreased from 0.219 h-1 to 0.0019 h-1 when the initial Cr(VI) concentration increased from 25 mg/L to 200 mg/L indicating a serious inhibition from Cr(VI) at high concen-tration. After Fourier transformed infrared(FTIR), scanning electron mi-croscope(SEM), energy disper-sive X-ray spectros-copy(EDS), X-ray photoelectron spectroscopy(XPS) and X-ray diffraction(XRD) analysis, it was proposed that Cr(VI) removal was not only attributed to the reducing functional groups(-NH, -OH) on cell surface but also due to the metabolism of bacterium. And mechanism of total Cr removal was adsorption coupled with formation of chromium hydroxide precipitation. EW1 was proposed to be a promising bacterium to remove Cr(VI) from wastewater.
