Efficient removal of fusidic acid from aqueous solution using synthesized zinc magnesium aluminum layered double hydroxide adsorbent

Pharmaceutical residues in the water have become a growing environmental concern because of their potential ecological and human health effects and their persistence. The Zn-Mg-Al layered double hydroxides (LDH) were prepared by the co-precipitation method, and their efficiency was tested as an adsorbent for the elimination of fusidic acid (FA) from aqueous solution. Characterization of the synthesized material was done by FTIR, SEM, XRD, EDS, BET, and TGA. The parameters affecting adsorption performance, such as pH, dosage of the adsorbent, contact time, initial concentration of FA and temperature, were investigated by batch adsorption experiments. The most efficient removal was obtained in 210 min at the optimum conditions of FA adsorbent dosage (1.25 g/L), agitation speed (250 rpm), concentration (20 mg/L), pH 5, and temperature (20 ± 1 °C), and showed the best agreement with the PSO model. Kinetic analysis suggested the PSO model best fitted the experimental data, while isotherm studies showed good agreement with the Freundlich model, indicating a heterogeneous adsorption behavior. Thermodynamic analysis shows that adsorption process was thermodynamically favorable. Besides, the reusability and structural stability of the adsorbent improved after calcination treatment, whereas the adsorption rate was slightly decreased. The results indicated that the Zn-Mg-Al LDH is a promising and economical adsorbent for the removal of pharmaceutical contaminants from aqueous stream.