An environmentally friendly carbon aerogels derived from waste pomelo peels for the removal of organic pollutants/oils

The frequent occurrence of organics/oils leakage incidents has caused a chain of serious negative influence on local water environment and ecological environment in the past few decades. In this paper, a novel family of biomass-based carbon aerogels was fabricated through the hydrothermal carbonization, freeze-drying and pyrolysis process using waste pomelo peels as the precursors. The internal morphology, structure, and chemical composition were characterized and investigated using scanning electron microscopy, transmission electron microscopy, X-ray diffraction, Fourier transform infrared spectroscopy, Raman spectroscopy and the nitrogen adsorption–desorption isotherm. The BET analysis showed that the specific surface area of the carbon aerogel could reach up to 466.0–759.7 m2/g when the carbonization temperature was in a range from 600 °C to 800 °C. It was found that the carbon aerogels derived from waste pomelo peels had excellent sorption ability for a variety of organic pollutants/oils and the sorption ability dropped slightly as the calcination temperature increased. In addition, the sorbent could be easily regenerated by simple physical treatments and kept a high sorption rate after five sorption-regeneration cycles.