Accumulation of Methylene Blue Dye by Growing Lemna minor

In the present investigation bioaccumulation studies were performed for the removal of Methylene Blue dye from an aqueous solution using live Lemna minor. The effect of various parameters such as the biosorbent dosage (1-3g), pH (3-83, 4, 5, 6, 7, 8) and initial dye concentration (2-10mg L-1) were studied. The maximum uptake capacity of the Methylene Blue using L. minor was observed as 10.93mg g-1 at a biosorbent dosage of 1g/300mL, at pH 7 and at 10mg L-1 initial dye concentration. The surface morphology was analyzed using Scanning Electron Micrograph (SEM) for analyzing micro and macropores present on the surface of the plant and the functional groups on the biosorbent were analyzed using Fourier transform infrared analyzer (FTIR) for increasing the electrostatic attraction between the plant surface and the dye molecules by adjusting the pH of the solution. Equilibrium data was analyzed using Langmuir and Freundlich adsorption isotherm models. The Freundlich adsorption isotherm was found to be fitted well. The effect of initial dye concentration on the growth of the plant was studied by obtaining the growth profile of the plant on the basis of the relative growth rate (RGR).