An investigation into the rapid removal of tetracycline using multilayered graphene-phase biochar derived from waste chicken feather

- Multilayered graphene-phase biochar (MGB) is prepared by carbonization and activation of waste chicken feather.
- High surface area (1838 m2/g) and excellent adsorbability are found with this green, economic and renewable material.
- Mechanism and Character are investigated to reveal the adsorption behavior of MGB.
- The MGB is tolerance in tough circumstances.
- Zeta potential of MGB was negative (pH < 3) and the regeneration ability was remarkable.

This study investigated the removal of tetracycline (TC) using multilayered graphene-phase biochar (MGB) derived from waste chicken feather. MGB was produced through a two-stage carbonization and KOH-activation method. MGB was characterized by scanning electron microscopy (SEM), transmission electron microscope (TEM), Fourier transform infrared (FT-IR), Raman spectra, Zeta potential and elemental analysis. Various chemical functional groups were demonstrated on the surface of MGB. MGB was featured by a very large BET surface area of 1838 m2/g. A rapid equilibrium (within 30 s) and an ultrahigh removal efficiency (up to 99.65%) were obtained when MGB was used in the adsorption of TCs. The adsorption processes were temperature-dependent and the maximum adsorption capacity of MGB was 388.33 mg/g at 30 °C. The data of adsorption isotherms and kinetics were represented well by the Langmuir and Elovich models, respectively. The chemical monolayer adsorption could play an important role in this process. Furthermore, the adsorption of MGB was tolerant with wide pH, high ionic strength and even co-existing anions. Regeneration experiments indicated the removal efficiency was still satisfied (96.61%) even after four cycles. These results have important implications for the future application of animal waste-derived adsorbents in the treatment of wastewater containing antibiotic residues.

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