Key Laboratory of Western China's Environmental Systems (Ministry of Education) and Key Laboratory for Environmental Pollution Prediction and Control, Gansu Province, College of Earth and Environmental Sciences, Lanzhou University, Lanzhou 730000, China.
Key Laboratory of Western China's Environmental Systems (Ministry of Education) and Key Laboratory for Environmental Pollution Prediction and Control, Gansu Province, College of Earth and Environmental Sciences, Lanzhou University, Lanzhou 730000, China.
Sci Total Environ. 2019 Dec 10;695:133800. doi: 10.1016/j.scitotenv.2019.133800. Epub 2019 Aug 5.
Three adsorbents, namely, original biochar (CLB), montmorillonite (MMT)-biochar composite (MBC), and magnetic MMT-biochar composite (MMBC) were successfully fabricated by one step pyrolysis of original cauliflower (Brassica oleracea L.) leaves, mixture of cauliflower leaves and MMT, and FeCl-laden mixture of cauliflower leaves and MMT under limited oxygen atmosphere, respectively. The characterizations of samples indicated that substantial MMT mineral particles and FeO nanoparticle were dispersed on the surface of MMBC. Due to the introduction of FeO, MMBC performed excellent magnetization property. The adsorption experiments of oxytetracycline (OTC) indicated that the maximum adsorption ability of MMBC was 58.85 mg·g, which was 2.63 times as large as CLB, also, larger than that of MBC. Meanwhile, pH, ionic strength, and humic acid (HA) performed slight effects for adsorption of OTC on MMBC. In addition, MMBC still removed 92% OTC after five regeneration cycles. Finally, primary mechanisms of OTC adsorption onto MMBC were attributed to hydrogen bonding and π-π reaction, and ion exchange reaction was considered to exist. Meanwhile, functional groups including Si-O-Al, Si-O-Si, Si-O, and FeO nanoparticles would provide extra binding sites for OTC adsorption. Therefore, MMBC had an obvious potential to apply into water purification as a reliable, low-cost, and environmentally friendly adsorbent.
三种吸附剂，即原始生物炭（CLB）、蒙脱土-生物炭复合材料（MBC）和磁性蒙脱土-生物炭复合材料（MMBC），分别通过一步热解原花椰菜（Brassica oleracea L.）叶、花椰菜叶和蒙脱土混合物以及花椰菜叶和蒙脱土负载 FeCl 的混合物，在有限氧气气氛下成功制备。样品的特性表明，大量的 MMT 矿物颗粒和 FeO 纳米颗粒分散在 MMBC 的表面。由于 FeO 的引入，MMBC 表现出优异的磁化性能。土霉素（OTC）的吸附实验表明，MMBC 的最大吸附能力为 58.85mg·g，是 CLB 的 2.63 倍，也大于 MBC。同时，pH 值、离子强度和腐殖酸（HA）对 OTC 在 MMBC 上的吸附影响较小。此外，MMBC 在五次再生循环后仍能去除 92%的 OTC。最后，OTC 吸附到 MMBC 上的主要机制归因于氢键和π-π反应，并且存在离子交换反应。同时，包括 Si-O-Al、Si-O-Si、Si-O 和 FeO 纳米颗粒在内的官能团将为 OTC 吸附提供额外的结合位点。因此，MMBC 作为一种可靠、低成本、环保的吸附剂，在水净化方面具有明显的应用潜力。
