Clay-Biochar Nanocomposite As a Media for the Removal of Oxytetracycline Antibiotic from Water

Oxytetracycline (OTC) is considered as one of the frequently used antibiotic in human and in the veterinary industries, release into environment and recorded in the wastewaters. Biochar has been received recent attention as a material for removing pharmaceuticals in aqueous media however, still the capacity needs to be increased further. This study investigates OTC sorption from water using nanocomposite derived from municipal solid waste biochar (MSW-BC) and montmorillonite. The adsorbents were characterized using powder X-Ray Diffraction (PXRD), Fourier-Transform Infrared (FTIR) spectroscopy, and Scanning Electron Microscope (SEM) before and after adsorbent treatment with OTC. Batch experiments were conducted to study the mechanisms involved in the adsorption with changing pH and time for 10 mg/L initial concentration of OTC at a pH range of 3.5-10 until 10 hrs. The SEM confirmed the successful binding of montmorillonite (MMT) onto the MSW-BC through a flaky structure along the porous morphology. Encapsulation of MMT onto MSW-BC was exhibited through changes in basal spacing of MMT via PXRD analysis. Results from FTIR spectra indicated the presence of functional groups for both pristine materials and composites that are involved in the adsorption. There was no considerable effect from the acidic pH while the basic pHs reduced OTC adsorption. Adsorption capacity ranged in 4-4.5 mg/g. Adsorption reached equilibrium at 8 hrs. The results indicated that the clay-biochar nano composite can be used for the removal of OTC in aqueous media.