Efficient tetracycline removal from aqueous solutions using ionic liquid modified magnetic activated carbon (IL@mAC)

Tetracycline (TCy) belongs to PPCPs is such a widely used antibacterial drug, which is discharged from urban wastewater treatment plants or agricultural effluents. Due to low metabolism, poor absorption, overuse, and misuse, TCy is considered as threat to environment and its removal from waste-water is vital. In this research, a novel ionic liquid modified magnetic activated carbon nanocomposite (IL@mAC) was synthesized, characterized, and the adsorption efficiency of IL@mAC for removal of TCy was investigated under different operational parameters of pH (3-11); dose of IL@mAC (0.01-0.1 g/50 mL); reaction time (30-240 min), and initial TCy concentration (50-1500 mg/L). The IL@mAC characterization was done using XRD, VSM, SEM-EDX, BET, and FTIR. Results of equilibrium experiment showed that the highest removal efficiency (similar to 98%) was obtained using 0.06 g of IL@mAC in 135 min at pH 7 and temperature 303 K. Considering the correlation coefficients (R-2) for different adsorption models, it can be deduced that adsorption of TCy onto IL@mAC was better followed by Langmuir (0.9985) in comparison to Freundlich (0.9322), and Temkin (0.9654) models. Furthermore, Langmuir adsorption capacity was observed to be 895.0 mg/g. The regeneration study showed that IL@mAC retained around 85% TCy adsorption efficiency after 6th cycle. Finally, the present study indicates that the IL@mAC is of a high applicability and has extremely high adsorbent capacity to remove TCy from water compared to most of other benchmark adsorbents reported in literature.