Lingling Rong,Ligui Wu,Tiao Zhang,Cui Hu,Haihui Tang,Hongcheng Pan,Xiaoming Zou
To improve the adsorption efficiency of pollutants by biochar, preparing graphene-like biochar (GBC) or nitrogen-doped biochar are two commonly used methods. However, the difference in the nitrogen doping (N-doping) effects upon the adsorption of pollutants by pristine biochar (PBC) and GBC, as well as the underlying mechanisms, are still unclear. Take the tetracycline (TC) as an example, the present study analyzed the characteristics of the adsorption of TCs on biochars (PBC, GBC, N-PBC, N-GBC), and significant differences in the effects of N-doping on the adsorption of TCs by PBC and GBC were consistently observed at different solution properties. Specifically, N-doping had varied effects on the adsorption performance of PBC, whereas it uniformly improved the adsorption performance of GBC. To interpret the phenomenon, the N-doping upon the adsorption was revealed by the QSAR model, which indicated that the pore filling (VM) and the interactions between TCs with biochars (Ead-v) were found to be the most important two factors. Furthermore, the density functional theory (DFT) results demonstrated that N-doping slightly affects biochar’s chemical reactivity. The van der Waals (vdWs) and electrostatic interactions are the main forces for TCs-biochars interactions. Moreover, N-doping mostly strengthened the electrostatic interactions of TCs-biochars, but the vdWs interactions of most samples remained largely unaffected. Overall, the revealed mechanism of N-doping on TCs adsorption by biochars will enhance our knowledge of antibiotic pollution remediation.
Xueyi Zhang,Wenshuang Sun,Yue Wang,Zhen Li,Xianqiang Huang,Tielong Li,Haitao Wang
In this study, we prepared a micron zero-valent iron/ N -doped graphene-like biochar (mZVI/NGB) composite using a mechanochemical method for tetracycline (TC) degradation through O 2 activation. The mZVI and NGB components formed a strong coupling catalytic system, with mZVI acting as an electron pool and NGB as a catalyst for H 2 O 2 generation. Under circumneutral pH (5.0–6.8), the mZVI/NGB composite exhibited exceptional TC removal efficiency, reaching nearly 100 % under optimal conditions. It also showed good tolerance to co-existing anions, such as Cl - , SO 4 2- , and humic acid. Further studies found that the TC degradation mechanism was mainly ascribed to the non-radical pathway ( 1 O 2 and electron transfer), and the Fe 2+ /Fe 3+ redox cycle on the composite's surface also played a crucial role in maintaining catalytic activity. This research contributes to the development of advanced materials for sustainable and effective water treatment, addressing pharmaceutical pollutant contamination in water sources.
危险品化学品经营许可证（带存储）