查看文章

Azo dyes and chromium (Cr) are released in the wastewater of leather processing industry during tanning process. Several species of bacteria have shown ability to degrade azo dyes individually; however, presence of Cr ions in industrial effluents may affect the bacterial efficiency of removing azo dyes from waste water. In this study, biodegradation of reactive black-5 dye was studied in a mineral salts medium (MSM) liquid culture in the presence of Cr ions. Two bacterial strains Psychrobacter alimentarius KS23 and Klebsiella oxytoca N7 capable of degrading azo dyes were used individually as well as in a consortium for the degradation of azo dyes. Cr was applied in the form of K₂ Cr₂ O₇, CrCl₃, Cr2 (SO₄)₃ at different concentrations (ranging from 0-250 mg L^-1) of Cr. The results showed that presence of Cr in mineral salt medium significantly inhibited the azo dye decolorization. In the absence of Cr salts …