Abstract In current study Lemna Minor (LM) has been utilized as the adsorbent for the removal of a reactive red 120 (RD-120), from aqueous solution using the batch adsorption technique under different conditions such as temperature, contact time and initial dye concentration at pH fixed 7. The optimum sorption conditions were found as following: contact time 90 min, initial dye concentration 25 mg/L and temperature 50 °C. Different thermodynamic parameters i.e., changes in standard free energy, enthalpy, and entropy have also been evaluated. The ΔH0 and ΔS0 values are thus found to be 5.17 KJ/mol and ΔS0 0.0342 J/K mol, respectively, while the ΔG0 values were -4.17, 4.89 and -5.38 J in 293-323 K and it has been found that the reaction was spontaneous and endothermic in nature. On the other hand, equilibrium parameters have been investigated with Langmuir and Freundlich. The result of experimental data indicates that Langmuir equation fit better than the other.
Keyword: Lemna Minor, Adsorption, Isotherm, Thermodynamic.