Gansu Key Laboratory for Environmental Pollution Prediction and Control, College of Earth and Environmental Sciences, Lanzhou University, Lanzhou, 730000, China.
Environ Sci Pollut Res Int. 2019 Mar;26(8):7463-7475. doi: 10.1007/s11356-019-04172-8. Epub 2019 Jan 17.
A novel magnetic attapulgite-biochar composite (MABC) derived from natural attapulgite, cauliflower leaves, and FeCl was successfully prepared as a low-cost adsorbent for oxytetracycline (OTC) removal from aqueous solution. Characterization experiments by different techniques suggested that attapulgite clay particles and FeO nanoparticles were successfully covered on the MABC surface. Compared with the pristine biochar (CLB) and attapulgite-biochar composite (ABC), MABC had the largest surface area, well-developed pore structure, and more surface oxygen-containing functional groups which could interact with organic pollutant via hydrogen bonding, π-π electron coupling, complexation, and ion exchange. The maximum adsorption capacity of MABC by the Langmuir model was 33.31 mg/g, which was dramatically higher than that of CLB and ABC. The effects of solution initial pH had little difference on the adsorption of OTC because of the buffering effect. Adsorbent-regeneration studies of MABC exhibited good reusability and separation property. All the results indicated that MABC could be used as a potential adsorbent because of its easy preparation and separation, high efficiency, wide pH range application, and abundant and cheap raw materials in the global ecosystem. Graphical abstract.
一种新型的磁性凹凸棒石-生物炭复合材料（MABC），由天然凹凸棒石、花椰菜叶和 FeCl 成功制备而成，是一种从水溶液中去除土霉素（OTC）的低成本吸附剂。不同技术的特征实验表明，凹凸棒石粘土颗粒和 FeO 纳米颗粒成功地覆盖在 MABC 表面。与原始生物炭（CLB）和凹凸棒石-生物炭复合材料（ABC）相比，MABC 具有最大的表面积、发达的孔结构和更多的表面含氧官能团，这些官能团可以通过氢键、π-π 电子偶联、络合和离子交换与有机污染物相互作用。MABC 通过 Langmuir 模型的最大吸附容量为 33.31mg/g，明显高于 CLB 和 ABC。由于缓冲作用，溶液初始 pH 对 OTC 吸附的影响差异很小。MABC 的吸附剂再生研究表现出良好的可重复使用性和分离性能。所有结果表明，由于 MABC 制备和分离简便、效率高、应用 pH 范围广、且在全球生态系统中具有丰富而廉价的原料，因此可将其作为一种潜在的吸附剂。
