Pig manure-derived nitrogen-doped mesoporous carbon for adsorption and catalytic oxidation of tetracycline.

Ordered nitrogen-doped mesoporous carbon (NMC) was successfully synthesized with pig manure as the precursor. The resulting NMC materials exhibited excellent capacity of adsorption and potassium persulfate (PS) activation when used as catalysts for the oxidative degradation of tetracycline antibiotics (tetracycline hydrochloride (TH) as the target). For an initial TH concentration of 35 mg/L, the maximum adsorption capacity of NMC material prepared at 700 °C (NMC700) was 122.0 mg/g, and the degradation efficiency in the PS reaction system was 94.8% within 120 min. Investigation of the mechanism indicated that the NMC700 material with specific surface area (SSA) of 275.5 m2/g and 0.7% graphitic N content, provided a large amount of active sites for adsorption and catalytic oxidation of TH. Based on the results of selective degradation and electron paramagnetic resonance (EPR) experiments, a non-radical pathway for the degradation of pollutants was proposed. Chronoamperometry evaluation also supported the conclusion that the NMC material enhanced electron transfer to activate persulfate, accelerating the removal of TH.