Optimization and kinetic studies on decolorization of Vat Green XBN by a newly isolated bacterial strain Proteus mirabilis PMS

Abstract The present study aims at evaluating the aerobic decolorization of Vat Green XBN by an isolated bacterium, Proteus mirabilis PMS from textile dye wastewater. Response surface methodology was applied for the optimization of the process parameters, including pH, temperature, and inoculum size. At optimum conditions, the strain PMS shows the maximum decolorization efficacy with pH 10.04, temperature 37 °C, and inoculum size of 8.46 % (v/v) where 94.96 % of 100 mg L−1 Vat Green XBN was decolorized within 20 h. Kinetics study was carried out using various approaches: Michaelis-Menten (Vmax =37 mg L−1 h−1 and Km =31.2 mg L−1), Lineweaver-Burk (Vmax = 29.92 mg L−1 h−1 and Km =35.33 mg L−1), and Eadie-hofstee model (Vmax =31.04 mg L−1 h−1 and Km =35.64 mg L−1), and the results showed that the degradation followed a first-order reaction. Decolorization was validated through spectroscopy and FT-IR analysis.