Enhanced phytoremediation and biosorption of cationic methylene blue dye by Acidomyces acidophilus ATCC 26774.

Abstract

In this study, the enhancement of the phytoremediation and biosorption properties of the cationic dye methylene blue using Acidomyces acidophilus ATCC 26774 were investigated. Inoculation with A. acidophilus ATCC 26774 increased the length of Bassica juncea roots by 82.3% and stems by 37.7% in the presence of 50 mg/L MB dye. Furthermore, the dried biomass of A. acidophilus ATCC 26774 showed superior removal capacity (87.1%) of MB dye. The maximum adsorption capacities of the biomass were investigated at pH 11 (176.8 mg/g) and 0.09 g/20 ml dried biomass (120.3 mg/g), respectively. The influence of contact times (0-360 min) and initial concentrations (30.0-357.5 mg/L) on the biosorption of MB dye was also investigated. In addition, A. acidophilus ATCC 26774 was characterized by Fourier transform infrared spectroscopy (FT-IR) and point of zero charge (pH_pzc). Equilibrium biosorption isotherms and kinetics results showed a Langmuir isotherm and pseudo-second-order kinetic models that fit well for MB dye biosorption. Monolayer biosorption, intraparticle diffusion, and chemisorption are predicted to play key roles in MB dye biosorption. In conclusion, A. acidophilus ATCC 26774 is proposed as an excellent plant growth promoting fungus and biosorbent with potential applications in the removal of cationic MB dye from the environment.