Mitigating environmental pollution by methyl orange via effective adsorption using modified layered double hydroxide

In alignment with global trends toward environmental and economic sustainability, this study focused on the preparation of layered double hydroxide (LDH) and its modification with activated carbon, as a sustainable material, to produce LDH-AC aimed at enhancing the sorption efficiency of methyl orange (MO) from aqueous solutions. Both materials were characterized via SEM, FTIR, XRD, and BET analysis confirming successful modification. Batch experiments revealed pseudo-second-order kinetics (R² > 0.99) with intra-particle diffusion as a rate-limiting step for LDH-AC. Langmuir isotherm fitting yielded maximum capacities of 71.43 mg/g (LDH) and 393.70 mg/g (LDH-AC) at 298 K and pH 5.5. Thermodynamic parameters (ΔH° = +18.54 and 35.77 kJ/mol for LDH and LDH-AC, respectively, and ΔG° = -0.069 and - 3.78 kJ/mol for LDH and LDH-AC, respectively, ) indicated an endothermic and spontaneous process. The greater efficiency of the LDH-AC composite was demonstrated by comparison with other sorbents reported in the literature. As a result, this sorbent is suggested as a practical way to eliminate MO while providing environmental benefits.