State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Beijing, 100083, PR China; School of Earth Sciences and Resources, China University of Geosciences, Beijing, 100083, PR China.
State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Beijing, 100083, PR China; School of Earth Sciences and Resources, China University of Geosciences, Beijing, 100083, PR China; China Household Electric Appliance Research Institute (CHEARI), Beijing, 100053, PR China.
Chemosphere. 2022 Sep;303(Pt 3):135264. doi: 10.1016/j.chemosphere.2022.135264. Epub 2022 Jun 8.
N-doping is an effective way to modify biochar for enhancing the adsorption capacity. The synthesis of N-doped biochar by the ball-milling method has been attractive due to its facile and eco-friendly approach with low energy consumption. However, the commonly used N-precursor NH·HO is environmentally harmful. It is needed to prepare safe and non-toxic N-doped biochar for large-scale production. Here, a urea N-doped biochar (U-MBC) was prepared by the ball-milling method and used for norfloxacin (NOR) removal. The results showed that U-MBC exhibited almost 4-fold higher adsorption capacity for NOR than pristine biochar in a wide pH range (3-9). The adsorption enhancement was owing to the enhancement of H-bonds, π-π electron donor-acceptor, and pore-filling interactions due to the N-doping and ball-milling method. Additionally, 89% of adsorbed NOR can be further removed after 6 h milling. The regenerated U-MBC still had a good adsorption capacity (46.27 mg g) and performed well in three cycles. The knowledge gained from this study could encourage researchers to use urea or similar safe N-precursors with the ball-milling method for the large-scale production of N-doped biochar to remove antibiotic organic pollutants in the environment.
N 掺杂是一种有效的方法，可以修饰生物炭以提高其吸附能力。由于球磨法具有简便、环保、能耗低的特点，因此通过球磨法合成 N 掺杂生物炭引起了人们的关注。然而，常用的 N 前体 NH·HO 对环境有害。需要制备安全无毒的 N 掺杂生物炭，以实现大规模生产。在这里，通过球磨法制备了一种尿素 N 掺杂生物炭（U-MBC），并将其用于诺氟沙星（NOR）的去除。结果表明，在较宽的 pH 范围（3-9）内，U-MBC 对 NOR 的吸附容量几乎比原始生物炭高 4 倍。吸附增强归因于 N 掺杂和球磨法增强了 H 键、π-π 电子供体-受体和孔填充相互作用。此外，经过 6 小时的研磨后，吸附的 89% NOR 可以进一步去除。再生的 U-MBC 仍具有良好的吸附能力（46.27 mg g），并且在三个循环中表现良好。本研究获得的知识可以鼓励研究人员使用尿素或类似的安全 N 前体与球磨法大规模生产 N 掺杂生物炭，以去除环境中的抗生素有机污染物。
