Super facile one-step synthesis of sugarcane bagasse derived N-doped porous biochar for adsorption of ciprofloxacin

A new N-doped biochar derived from sugarcane bagasse (NSB) was prepared by one-pot pyrolysis with sugarcane bagasse as feedstock, melamine as nitrogen source and NaHCO3 as pore-forming agent, and then NSB was used to adsorb ciprofloxacin (CIP) in water. The optimal preparation conditions of NSB were determined based on the evaluation index of adsorbability of NSB for CIP. SEM, EDS, XRD, FTIR, XPS and BET characterizations were used to analyze the physicochemical properties of the synthetic NSB. It was found that the prepared NSB had excellent pore structure, high specific surface area and more nitrogenous functional groups. Meanwhile, it was demon-strated that the synergistic interaction between melamine and NaHCO3 increased the pores of NSB and the largest surface area of NSB was 1712.19 m2/g. The CIP adsorption capacity of 212 mg/g was obtained under optimal parameters as follows: NSB amount 0.125 g/L, initial pH 6.58, adsorption temperature 30 degrees C, CIP initial concentration 30 mg/L and adsorption time 1 h. The isotherm and kinetics studies elucidated that the adsorption of CIP conformed both D-R model and Pseudo-second-order kinetic model. The high CIP adsorption capacity of NSB for CIP was due to the combined filling pore, 7C-7C conjugation and hydrogen bonding. All results demon-strated that adsorption of CIP by the low-cost N-doped biochar of NSB is a reliable technology for the disposal of CIP wastewater.

Automated summary

A new N-doped biochar (NSB) was prepared by one-pot pyrolysis using sugarcane bagasse, melamine, and NaHCO3 as feedstock, nitrogen source, and pore-forming agent, respectively. The physicochemical properties of NSB were characterized by SEM, EDS, XRD, FTIR, XPS, and BET analyses, confirming its excellent pore structure, high specific surface area, and nitrogenous functional groups. The optimized conditions for CIP adsorption by NSB were determined, and a CIP adsorption capacity of 212 mg/g was achieved under these conditions. The adsorption mechanism involved pore filling, 7C-7C conjugation, and hydrogen bonding. This study demonstrates the reliable technology of using low-cost NSB for the treatment of CIP wastewater.