One-step synthesis of iron and nitrogen co-doped porous biochar for efficient removal of tetracycline from water: Adsorption performance and fixed-bed column

Abstract

Here, Fe/N co-doped porous biochars (FeNKBCs) were obtained by grinding corncob, CH₃COOK, FeCl₃·6H₂O, and C₃H₆N₆ via one-step synthesis and were applied to remove antibiotics from wastewater. Notably, CH₃COOK had an excellent porous activation ability. The developed nanotubular structure of Fe1N2KBC had a high pore volume (V_total) (1.2131 cm³/g) and specific surface areas (SSA) (2083.54 m²/g), which showed outstanding sorption abilities for TC (764.35 mg/g), OTC (560.82 mg/g), SMX (291.45 mg/g), and SMT (354.65 mg/g). The adsorption process of TC was controlled by chemisorption. Moreover, Fe1N2KBC has an excellent dynamic adsorption performance (620.14 mg/g) in a fixed-bed column. The properties of SSA, V_total, and the content of graphite N and Fe-N were positively correlated with TC adsorption capacity. The high performance of TC removal was related to π-π stacking, pore-filling, hydrogen bond, and electrostatic interaction. Fe1N2KBC possessed stable sorption amounts in pH 2-12 and actual water, and well reuse performance. The results of this work present an effective preparation method of Fe/N porous biochar for TC-contaminated water remediation.

Keywords: Adsorption performance; Antibiotics; Fe/N addition; Fixed-bed column; Porous biochar.