Removal of methyl orange from aqueous solution using synthetic clay type MgAl-LDH: Characterization, Isotherm and thermodynamic studies

The MgAl-LDH adsorbent (2:1) was developed by the urea method and used as an adsorbent for the removal of methyl orange from aqueous solution. The synthesized adsorbent was characterized by a different analytical technique: scanning electron microscope SEM, X-ray diffraction (XRD) and infrared spectroscopy (FT-IR). The effect of adsorption parameters such as solution pH, initial concentration of dye, and the temperature was studied using a static system. X-ray diffraction analysis of the samples confirms the crystal structure of the MgAl-LDH material. The MgAl-LDH adsorbent was efficient in removing MO from aqueous solution, and maximum removal of 98.5 % was observed in the pH range from 2 to 10. The maximum adsorption capacity of MgAl-LDH (2:1) was calculated from the Langmuir isotherm; the maximum quantity is 1250 mg. g-1. The determination of the thermodynamic parameters indicates that the reaction between methyl orange and MgAl-LDH (2:1) is spontaneous and exothermic (ΔH°<0 and ΔG°<0).It can be concluded that LDH adsorbent can be used effectively for the removal of anionic dyes from industrial wastewater.