Abstract
In order to examine the decolorization of dyeing effluent by an enzyme, aqueous solutions of two kinds of dyes, copper formazan dyes (C. I. Reactive Blue 220) and disazo dyes (C. I. Acid Red 299), were treated with bilirubin oxidase (BO). By measuring the visible and UV absorption spectra of the two aqueous solutions to which the enzyme was added, it was found that B 220 was decolorized at 20°C and nonadjusted pH (pH 5.85), at 37°C and nonadjusted pH (pH 6.18) for 299. The variation of temperature (20°C and 37°C) and pH (nonadjusted pH—pH 6±0.2— and pH 8.4), however, hardly affected the decolorizing rate. In conclusion, it was confirmed that BO can efficiently decolorize dye solutions even at ordinary temperatures and neutral pH, without any adjustment.
