EDTA-interlayer modified Mg/Fe layered double hydroxides for enhanced adsorption of methyl orange: Adsorption performance and mechanism study

Abstract

Herein, we explored the efficacy of ethylenediaminetetraacetic acid (EDTA) intercalation modified layered double hydroxides (LDHs) composites for removing the anionic dye methyl orange (MO) from aqueous solutions. EDTA intercalated layered hydroxides (EDTA-Mg/Fe LDHs) with a 4:1 Mg/Fe molar ratio have been successfully prepared and thoroughly characterized using SEM-EDS, FTIR, XRD, XPS, UV-Vis and Zeta potential analysis. Batch adsorption experiments were conducted to evaluate the adsorption performance of the innovative adsorbent on MO. The results indicated successful EDTA loading into Mg/Fe LDHs, exhibiting excellent adsorption performance for MO. At pH 6.0, with a 0.03 g adsorbent dose, MO removal exceeded 91.10% within 90 min, following a pseudo second order kinetic model. The maximum adsorption capacity reached 1207.43 mg/g, fitting well with the Redlich Peterson model. Thermodynamic parameters suggested a spontaneous and favorable adsorption process. Furthermore, we assessed the desorption and regeneration effectiveness of EDTA-Mg/Fe LDHs, emphasizing the importance of developing cost-effective and environmentally friendly adsorbents with practical applications and scientific significance.