Study of the effect of weak magnetic field on the decolorization of azo dye by Fe-based amorphous alloy powders

Fe-Si-B amorphous alloy ribbons were melt-spun, and the amorphous powders were made by ball-milling the ribbons. The azo dye direct blue 2B was decolorized by the amorphous alloy powders. We made apreliminary study towards the weak magnetic field's effect on the decolorization of azo dye by Fe-based amorphous alloy powders via manipulating the magnetic field intensity generated by the Helmholtz coils, the dosage of the amorphous alloy powders. It was found that within certain magnetic field intensity range, increasing the intensity will result in the increase of decolorization rate. With H=3 980 A/m, the t_(1/2) was 5.0 min, and the decolorization rate was increased by 40% compared to that of H=0 A/m. With the increase of the Fe-based amorphous alloy powder dosage, the positive impact of the magnetic field on the decolorization rate was improved at firstand then stabilized.