Biodegradation of reactive blue 19 with simultaneous electricity generation by the newly isolated electrogenic Klebsiella sp. C NCIM 5546 bacterium in a microbial fuel cell

Abstract

Reactive Blue-19 (RB19) is an anthraquinone based vinylsulphone dye, which is very difficult to degrade by chemical oxidation because its anthraquinone structure is stabilized by resonance. It has 75–80% fixation efficiency on the cellulose (cotton textiles) and the unfixed dye persists in the environment for long periods. Therefore, textile industry effluents containing reactive blue (RB) 19 dye in a significant concentration need to be treated. Microbial fuel cell (MFC) is the newest approach for generating energy (electricity-bioelectricity) from the textile wastewater using bacteria. In this study, synthetic textile wastewater containing Reactive Blue 19 (RB19) dye (50 mg/L to 800 mg/L) was used to generate electricity with the newly isolated electrogenic bacterium Klebsiella sp. C. The MFC produced the current density of 533 mA/m2 and power density of 84 mW/m2. The decolorisation efficiency by Klebsiella sp. C for RB19 was 90% within 24 h under optimised conditions i.e. pH 7, temperature of 37 °C, 6 g/L glucose concentration and glucose to microbe ratio of 60. The intermediates identified by GCMS analysis included oxalic acid, indene- 1, 3- dione and hydroquinone. These results indicated that Klebsiella sp. C could be considered as a new bacterium for electricity generation along with treatment of RB19 containing effluent.