Removal of Basic Blue 3 from aqueous solution by Corynebacterium glutamicum biomass: Biosorption and precipitation mechanisms

The waste biomass generated from mono sodium glutamate fermentation process, Corynebacterium glutamicum, was evaluated as a biosorbent for the removal of Basic Blue 3 (BB 3), as a model cationic dye, from aqueous solution. A series of batch experiments to study pH edge, precipitation of dye, isotherms and kinetics were undertaken. The solution pH was found to be an important factor in biosorption of BB 3. With increasing the pH, the uptake of BB 3 increased, except at a pH below 2. At pH values below 2, the precipitation of BB 3 occurred rather than biosorption, which resulted in overestimation of the sorption performance. The sorption process could reach quickly to equilibrium after 1 min. The Langmuir and Freundlich models were used to fit the experimental data at different pH conditions. Between them, the Langmuir model described the experimental data very well with high correlation coefficients. Furthermore, C. glutamicum was easily eluted by shifting the solution pH, making repeated sorption/desorption cycle (up to 4 times) possible without significant performance decrease.