Understanding effects of chemical structure on azo dye decolorization characteristics by Aeromonas hydrophila

摘要: This novel comparative study tended to disclose how the molecular structures present in seven azo dyes including two types of (i.e., naphthol type dyes--Reactive Black 5 (RB 5), Reactive Blue 171 171), Green 19 (RG19), Red 198 (RR198), 141 (RR141), and non-naphthol dyes--Direct Yellow 86 (DY86), 84 (RY84)) affected color removal capability Aeromonas hydrophila. Generally speaking, decolorization rate dye with hydroxyl group at ortho bond was faster than that without group, except RG19. The electron-withdrawing groups (e.g., sulfo RR198, RB5 RR141) would be easier decolorized electron-releasing -NH-triazine RB171 RG19). In addition, containing more showed significantly decolorization. group) para could preferred for those meta DY86 RY84). former provided effective resonance effects withdraw electrons from bond, causing highly electrophilic rates reductive biodecolorization. However, since substituent caused steric hindrance near linkage(s), favorable SO(2)(CH(2))(2)SO(4)(-) RR198 RB5) Thus, ranking position escalate para>ortho>meta. suggested both positions substituents on aromatic ring electronic characteristics all performance biodecolorization A.