Thermally carbonization biochar produced from
a traditional Chinese herbal medicine waste (
Astragalus mongholicus
residue) was investigated for its performance
in ciprofloxacin adsorption. Batch sorption experiments
were conducted, and scanning electron microscopy, Fourier
transform infrared spectroscopy, X-ray photoelectron
spectroscopy and Brunauer–Emmett–Teller surface area
analyses were employed to characterize the biochar. The
results demonstrated that thermal activation process
improves the adsorbent characteristics. Biochar produced
at 800 °C had the best adsorption capacity, a better pore
structure and the largest surface areas. The adsorption
process fit well to a pseudo-second-order kinetics model.
The adsorption isothermal model results revealed that the
adsorption process of ciprofloxacin is described better by
the Freundlich isotherm and the type of adsorption is a
chemical process. The maximum adsorption of ciprofloxacin
occurred at pH 7. The present research demonstrated
that
A. mongholicus biochar might be an attractive
and cost-effective adsorbent with good adsorption performance
for removing ciprofloxacin from water solution.
