Removal of erythromycin antibiotic from the aqueous media using magnetic graphene oxide nanoparticles

The presence of antibiotic drugs in the aquatic environment causes many health and environmental problems. The purpose of this study was to investigate the removal efficiency of erythromycin antibiotic from aqueous media using magnetic graphene oxide nanoparticles. Therefore, in the batch system, to assess the adsorption efficiency, the effect of different parameters such as pH (3-11), adsorbent dose (0.01-0.05 g), a contact time (10-120 min), initial concentration of erythromycin antibiotic (1-100 mg/L), and temperature (288-313 K) was evaluated. The results showed that the maximum amount of erythromycin adsorption occurred in conditions of pH = 3, the antibiotic concentration of 100 mg/L, contact time of 120 min, a temperature of 313 K, and an adsorbent dose of 0.01 g. Thermodynamic parameters showed that the adsorption process of erythromycin antibiotic in the temperature range of 288 to 313 K is spontaneous and endothermic. The coefficients of determination and adsorption rate constant calculated using the pseudo-second-order model were R2 = 0.99 and k2 = 0.0004, respectively. The calculation based on the first-order model found R2 = 0.2 and k1 = -0.0199; it confirms that the pseudo-second-order model describes the laboratory data better than the first-order model. Meanwhile, the adsorption isotherms showed that antibiotic adsorption follows the Langmuir equation. According to the results of this research, a magnetic nanographene adsorbent with a high efficiency of 63.93% can be used to remove erythromycin from aqueous media.