College of Natural Resources and Environment, Northwest A&F University, Yangling, Shaanxi 712100, China.
Department of Transportation and Environment, Shenzhen Institute of Information Technology, Shenzhen, Guangzhou 518172, China.
Sci Total Environ. 2020 Aug 20;731:138806. doi: 10.1016/j.scitotenv.2020.138806. Epub 2020 Apr 25.
The objective of this work is to find a simple and environmentally friendly way to prepare high efficiency adsorbent from maize stover by cellulase. The characteristics of the original maize cob (MC), maize husk (MH), maize straw (MS), and its cellulase modified form (MMC, MMH and MMS) were detected by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS). Batch adsorption experiments indicated that the adsorption followed the pseudo-second-order kinetic model, and the adsorption capacity of sulfamethazine (SMT) to adsorbents was in order of MMC > MMS > MMH > MC > MS > MH. The adsorption isotherm data of SMT on original materials were consistent with Freundlich models, while Henry models were more suitable for the modified materials. The adsorption was affected by pH and ionic strength which demonstrated the interaction between π-π EDA and H bonds might be an important factor in the adsorption of SMT on maize stover. The results of FTIR and two-dimensional correlation spectroscopy (2D-COS) analysis further demonstrated that oxhydryl and aromatic structures in the modified maize stover could interact with SMT via H bonds and π-π EDA interaction, respectively. This work provides a green way to remove SMT from aqueous solution, and new insights into the mechanisms of adsorption of SMT on stover materials.
本工作旨在寻找一种简单、环保的方法，用纤维素酶从玉米秸秆中制备高效吸附剂。通过 X 射线衍射（XRD）、傅里叶变换红外光谱（FTIR）、扫描电子显微镜（SEM）和 X 射线光电子能谱（XPS）对原玉米穗（MC）、玉米皮（MH）、玉米秸秆（MS）及其纤维素酶修饰形式（MMC、MMH 和 MMS）的特性进行了检测。批量吸附实验表明，吸附符合准二级动力学模型，磺胺甲噁唑（SMT）对吸附剂的吸附容量顺序为 MMC> MMS> MMH> MC> MS> MH。SMT 在原物料上的吸附等温线数据与 Freundlich 模型一致，而 Henry 模型更适合改性物料。吸附受 pH 和离子强度的影响，表明π-π EDA 和氢键之间的相互作用可能是 SMT 在玉米秸秆上吸附的一个重要因素。FTIR 和二维相关光谱（2D-COS）分析的结果进一步表明，改性玉米秸秆中的羟基数和芳构结构分别通过氢键和π-π EDA 相互作用与 SMT 相互作用。这项工作为从水溶液中去除 SMT 提供了一种绿色方法，并为 SMT 在秸秆材料上的吸附机制提供了新的见解。
