| Popis: |
Reactive Black 5 is one of the most widely used dye in textile and other industries. It is one of the significantly toxic azo dye which poses a serious threat to the environment when discharged into water bodies. A bacterial isolate showed 98% dye removal from aqueous medium within 38hours under optimum parameters pH 7, temperature 400C, in the presence of 1% yeast extract as a co-substrate, and 25% inoculum size at an initial concentration of 50mg/l. Kinetic and thermodynamic study revealed the decolorization reaction is a first order non- spontaneous reaction. The highest rate constant 0.0523 was observed at 318K. Further ΔH, ΔG and ΔS, Ea was estimated using Eyring Polanyi equation was 20.80KJ/mol, -0.1KJ/ Mk respectively. LC-MS analysis revealed that decolorization was due to degradation of RB5 by cleavage of azo-bond by the bacterium, with the formation of s 3,6,8-trihyroxynapthalene and phthalic acid as degradation products. |
