Abstract
An azo dye, Orange II was decolorized and degraded by two-stage-treatment of chemical reduction by using zero-valence tin and biological oxidation. Zero-valence tin decolorized Orange II under acidic conditions, and produced the two aromatic amines, p-aminobenzene sulphonic acid (ABS) and 1-amino-2-naphthol (1A2N). By the enrichment culture using ABS and/or 1A2N as the sole carbon source, ABS-degrading consortium and Pseudomonas aeruginosa m2 as 1A2N-degrading bacterium were obtained. When the co-culture of P. aeruginosa m2 and ABS-degrading consortium was performed in the decolorized solution of Orange II by tin, the isolated strains exerted their degradation activities against each aromatic amine during the co-culture. The recalcitrant complex which was formed between ABS and 1A2N through auto-oxidation remained during the co-culture time. However, the elimination of the complex and the enhancement of ABS degradation were observed when tin was mixed in the co-culture.
