Seaweed-Derived Hierarchically Porous Carbon for Highly Efficient Removal of Tetracycline

Herein we present a facile approach for the preparation of a novel hierarchically porous carbon, in which seaweeds serve as carbon source and KOH as activator. The fabricated KOH-activated seaweed carbon (K-SC) displays strong affinity towards tetracycline with maximum uptake quantity of 853.3 mg/g, significantly higher than other tetracycline adsorbents. The superior adsorption capacity ascribes to large specific surface area (2614 mbegin{document}$ ^2 $end{document}/g) and hierarchically porous structure of K-SC, along with strong begin{document}$ pi $end{document}-begin{document}$ pi $end{document} interactions between tetracycline and K-SC. In addition, the as-prepared K-SC exhibits fast adsorption kinetics, capable of removing 99% of tetracycline in 30 min. Meanwhile, the exhausted K-SC can be regenerated for four cycling adsorption without an obvious degradation in capacities. More importantly, pH and ionic strengths barely affect the adsorption performance of K-SC, implying electrostatic interactions hardly play any role in tetracycline adsorption process. Furthermore, the K-SC packed fixed-bed column (0.1 g of adsorbents) can continually treat 2780 mL solution spiked with 5.0 mg/g tetracycline before reaching the breakthrough point. All in all, the fabricated K-SC equips with high adsorption capacity, fast adsorption rate, glorious anti-interference capability and good reusability, which make it hold great feasibilities for treating tetracycline contamination in real applications.