Characterization and ciprofloxacin adsorption properties of activated carbons prepared from various agricultural wastes by KOH activation

Abstract

Agricultural waste is a renewable and readily available resource that is used as a precursor to synthesize coal to reduce production costs. Significantly, valorizing it would greatly improve the quality of living in rural and remote areas. In this study, agricultural waste from straw, Limonia acidissima shell, avocado shell, tea waste and banana peel were used as precursors to prepare activated carbon. The desired surface area and pore size of carbonized materials was achieved by the chemical activation method, using KOH as an activating agent at a temperature of 500 °C. Scanning electron microscopy (SEM) and X-ray diffraction were used to determine surface morphology and amorphous carbon formation. The surface functional groups of carbonized materials were characterized by Fourier transform infrared spectroscopy (FT-IR) and N2adsorption-desorption isotherms, which revealed the specific surface area (BET) of the five activated carbon materials. The analytical results show that the activated carbon produced from straw exhibits superior characteristics and the highest ciprofloxacin removal efficiency among the five types of activated carbon. The surface area reached 494.92 cm2/g and total pore volume reached 0.494 cm3/g. Moreover, the ciprofloxacin adsorption efficiency reached 93.34% at a concentration of 20 mg/L. The results of this study indicate that activated carbon made from industrial waste has the potential to be used for removing antibiotics from aqueous environment.