Efficient Adsorption of Chlortetracycline and Ibuprofen Onto Mg–Al Layered Double Hydroxide: Equilibrium, Kinetic, and Thermodynamic Studies

ABSTRACT

Magnesium–aluminum layered double hydroxide (Mg─Al LDH) with a Mg/Al molar ratio of 2:1 was synthesized by a simple co‐precipitation method and evaluated for the simultaneous removal of chlortetracycline (CTC) and ibuprofen (IBP) from aqueous solutions. SEM–EDX, FTIR, and XRD analyses confirmed the successful formation of a well‐defined layered structure with a basal spacing of 7.65 Å and a pHpzc of 6.15. Batch adsorption experiments showed rapid equilibrium within 30 min for CTC and 60 min for IBP, with removal efficiencies reaching 99% under optimal conditions (293 K, adsorbent dosage 2 g L ^{− 1} , initial concentration 50 mg L ^{− 1} , pH 7). The adsorption kinetics followed the pseudo‐second‐order model for CTC and the pseudo‐first‐order model for IBP, while equilibrium data were best described by the Langmuir isotherm, yielding maximum adsorption capacities of 121.61 mg g ^{− 1} for CTC and 100.41 mg g ^{− 1} for IBP. Thermodynamic parameters indicated spontaneous and exothermic adsorption, with stronger interactions for CTC. The uncalcined Mg─Al LDH exhibited adsorption performance comparable to or exceeding that of many modified LDH‐based materials, highlighting its potential as a simple, cost‐effective, and sustainable adsorbent for pharmaceutical wastewater treatment.